Attenuation of Hypersonic Second Mode Instability with Discrete Surface Roughness on Straight Blunt Cones

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Total Pages : 194 pages
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Book Synopsis Attenuation of Hypersonic Second Mode Instability with Discrete Surface Roughness on Straight Blunt Cones by : Christopher Haley

Download or read book Attenuation of Hypersonic Second Mode Instability with Discrete Surface Roughness on Straight Blunt Cones written by Christopher Haley and published by . This book was released on 2021 with total page 194 pages. Available in PDF, EPUB and Kindle. Book excerpt: Hypersonic boundary layer research has studied surface features, such as isolated or distributed roughness, extensively for turbulence tripping. However, there are reports of a counterintuitive phenomenon within the literature whereby surface roughness can delay the onset of laminar-turbulent transition. The reports did not attract widespread attention, leaving the phenomenon's underlying mechanism uninvestigated for several decades. A renewed interest in boundary layer control strategies motivated Fong and Zhong in 2012 to conduct an extensive numerical study on what has been termed the ``roughness effect''. The research found that roughness elements immersed within the boundary layer and placed at the synchronization location for a particular unstable frequency can attenuate higher unstable frequencies while amplifying lower unstable frequencies. Thus, providing a passive means to delay laminar-turbulent transition with discrete surface roughness. However, these previous numerical investigations are limited to a flat plate geometry, 2-D spanwise roughness, limited in the scope of their freestream Mach number, and focus exclusively on Mack's second mode instability. In order to advance our knowledge of the roughness effect, the objectives of this dissertation are fourfold: (1) To investigate the roughness effect on a straight blunt cone geometry, (2) To investigate the long-term downstream consequences of the roughness effect, (3) Provide experimental evidence of second mode attenuation in a flow with a growing boundary layer containing a range of unstable frequencies, and the consequences of off-design flow conditions, and (4) To investigate the appearance of the supersonic mode in a low-enthalpy warm wall flow of the current study. A combined approach of direct numerical simulation, body-fitted surface roughness, and linear stability theory are used to numerically investigate the roughness effect. Four cases are computed as part of the research objective. Case C.1 is a Mach 8 flow computed for the design of a passive transition-delaying roughness configuration, along with studying the roughness effect on a straight blunt cone. Case C.1-Ext is a longer cone simulation of C.1 and is computed to investigate the long-term downstream response of the roughness effect. C.2 is similar to C.1 except for a smaller nose radius and is computed for experimental validation. The last case, C.3, is a Mach 5 flow and is computed to study the roughness effect on a straight blunt cone in off-design flow conditions and for experimental validation. The first objective to investigate the roughness effect on a straight blunt cone advances the research from a flat plate to more realistic test article geometries. Much of the experimental work done in hypersonic boundary layer stability research is done on straight cones due to the axisymmetric flows in hypersonic wind tunnels. The investigation found that the roughness effect behaves like a flat plate where unstable frequencies higher than the synchronization frequency are attenuated, and lower frequencies are amplified. The investigation also found that some flow features around the roughness elements, such as separation zones, are either smaller in size or absent in conical flow fields. The investigation also confirmed that the second mode's attenuation is a result of the element's proximity to the synchronization location and not due to its proximity with the branch I/II neutral points. The long-term downstream effect of second mode attenuation is also investigated for a single roughness and roughness array. The numerical investigation found that the range of targeted frequencies is attenuated as expected, especially for the roughness array, which proves to be effective at attenuating unstable frequencies over a longer distance. However, the amplitudes of frequencies below the targeted range grow many times higher than they would have otherwise on a cone with no roughness. The passive transition-delaying control strategy, rather than dissipating the disturbance energy, acts to transfer the energy to lower unstable frequencies, guaranteeing eventual turbulent transition. The result demonstrates that roughness must be applied to the entire cone to have an effective control strategy. The experimental results in this dissertation come from a joint numerical and experimental investigation of transition-delaying roughness with Dr. Katya Casper at Sandia National Laboratories. A numerical simulation is undertaken to design a surface roughness array that would attenuate Mack's second mode instability and maintain laminar flow over a Mach 8 hypersonic blunt cone. Multiple experimental runs at the Mach 8 condition with different Reynolds numbers are performed, as well as an off-design Mach 5 condition. The roughness array successfully delays transition in the Mach 8 case as intended but does not delay transition in the Mach 5 case. For validation and further analysis, numerical cases C.2 and C.3 are computed using the Mach 8 and Mach 5 experimental flow conditions. Stability analysis of case C.2 shows that the roughness array is adequately designed to attenuate the second mode. Analysis of case C.3 reveals the Mach 5 boundary layer is dominated by Mack's first mode instability and is not attenuated by the array. This investigation of multiple flow conditions combined with experimental results helps validate the numerical code and provides empirical evidence for the roughness effect. While investigating transition delaying surface roughness, acoustic-like waves are observed emanating from the boundary layer of case C.1-Ext. The acoustic-like wave emissions are qualitatively similar to those attributed to the supersonic mode. However, the supersonic mode responsible for such emissions is often found in high-enthalpy flows with highly cooled walls, making its appearance in a flow with relatively low freestream enthalpy and a warm wall unexpected. Stability analysis on the steady-state solution reveals an unstable mode S with a subsonic phase velocity and a stable mode F whose mode F- branch takes on a supersonic phase velocity. The stable supersonic mode F is thought to be responsible for the acoustic-like wave emissions. Unsteady simulations are carried out using blowing-suction actuators at two different surface locations. Analysis of the temporal data and spectral data reveals constructive/destructive interference occurring between a primary and a satellite wave packet in the vicinity of the acoustic-like wave emissions, which has a damping effect on individual frequency growth. Based on this study's results, it is concluded that a supersonic discrete mode is not limited to high-enthalpy, cold wall flows and that it does appear in low-enthalpy, warm wall flows; however, the mode is stable.

Effects of Thermochemical Nonequilibrium on Hypersonic Boundary-Layer Instability in the Presence of Surface Ablation Or Isolated Two-Dimensional Roughness

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Total Pages : 251 pages
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Book Synopsis Effects of Thermochemical Nonequilibrium on Hypersonic Boundary-Layer Instability in the Presence of Surface Ablation Or Isolated Two-Dimensional Roughness by : Clifton Mortensen

Download or read book Effects of Thermochemical Nonequilibrium on Hypersonic Boundary-Layer Instability in the Presence of Surface Ablation Or Isolated Two-Dimensional Roughness written by Clifton Mortensen and published by . This book was released on 2015 with total page 251 pages. Available in PDF, EPUB and Kindle. Book excerpt: The current understanding of the effects of thermochemical nonequilibrium on hypersonic boundary-layer instability still contains uncertainties, and there has been little research into the effects of surface ablation, or two-dimensional roughness, on hypersonic boundary-layer instability. The objective of this work is to study the effects of thermochemical nonequilibrium on hypersonic boundary-layer instability. More specifically, two separate nonequilibrium flow configurations are studied: 1) flows with graphite surface ablation, and 2) flows with isolated two-dimensional surface roughness. These two flow types are studied numerically and theoretically, using direct numerical simulation and linear stability theory, respectively. To study surface ablation, a new high-order shock-fitting method with thermochemical nonequilibrium and finite-rate chemistry boundary conditions for graphite ablation is developed and validated. The method is suitable for direct numerical simulation of boundary-layer transition in a hypersonic real-gas flow with graphite ablation. The new method is validated by comparison with three computational data sets and one set of experimental data. Also, a thermochemical nonequilibrium linear stability theory solver with a gas phase model that includes multiple carbon species, as well as a linearized surface graphite ablation model, is developed and validated. It is validated with previously published linear stability analysis and direct numerical simulation results. A high-order method for discretizing the linear stability equations is used which can easily include high-order boundary conditions. The developed codes are then used to study hypersonic boundary-layer instability for a 7 deg half angle blunt cone at Mach 15.99 and the Reentry F experiment at 100~kft. Multiple simulations are run with the same geometry and freestream conditions to help separate real gas, blowing, and carbon species effects on hypersonic boundary-layer instability. For the case at Mach 15.99, a directly simulated 525~kHz second-mode wave was found to be significantly unstable for the real-gas simulation, while in the ideal-gas simulations, no significant flow instability is seen. An N factor comparison also shows that real-gas effects significantly destabilize the flow when compared to an ideal gas. Blowing is destabilizing for the real gas simulation and has a negligible effect for the ideal gas simulation due to the different locations of instability onset. Notably, carbon species resulting from ablation are shown to slightly stabilize the flow for both cases. For the Reentry F flow conditions, inclusion of the ablating nose cone was shown to increase the region of second mode growth near the nose cone. Away from the nose cone, the second mode was relatively unaffected. Experimental and numerical results have shown that two-dimensional surface roughness can stabilize a hypersonic boundary layer dominated by second-mode instability. It is sought to understand how this physical phenomenon extends from an airflow under a perfect gas assumption to that of a flow in thermochemical nonequilibrium. To these ends, a new high-order shock-fitting method that includes thermochemical nonequilibrium and a cut-cell method, to handle complex geometries unsuitable for structured body-fitted grids, is presented. The new method is designed specifically for direct numerical simulation of hypersonic boundary-layer transition in a hypersonic real-gas flow with arbitrary shaped surface roughness. The new method is validated and shown to perform comparably to a high-order method with a body-fitted grid. For a Mach 10 flow over a flat plate, a two-dimensional roughness element was found to stabilize the second mode when placed downstream of the synchronization location. This result is consistent with previous results for perfect-gas flows. For a Mach 15 flow over a flat plate, a two-dimensional surface roughness element stabilizes the second-mode instability more effectively in a thermochemical nonequilibrium flow, than in a corresponding perfect gas flow.

Receptivity of Straight Blunt Cones to Broadband Freestream Pulse Disturbances for Transition Prediction in Hypersonic Flow

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Total Pages : 0 pages
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Book Synopsis Receptivity of Straight Blunt Cones to Broadband Freestream Pulse Disturbances for Transition Prediction in Hypersonic Flow by : Simon He

Download or read book Receptivity of Straight Blunt Cones to Broadband Freestream Pulse Disturbances for Transition Prediction in Hypersonic Flow written by Simon He and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Traditional stability analysis for hypersonic flows has focused on the development and relative amplification of a dominant disturbance mode, namely Mack's second mode. However, conventional $e^N$ method transition estimates based purely on the relative amplification of the second mode ignore the receptivity mechanisms which govern the response of a flow to different environmental disturbances. These receptivity mechanisms are now known to play a much more significant role in the laminar-to-turbulent transition of hypersonic flows, and numerous theoretical, computational, and experimental studies have been made to characterize them. Computational studies in particular are useful due to the large amount of high precision data they can generate with a relatively low cost, while experimental receptivity studies face difficulties due to the high noise environments present in conventional hypersonic windtunnels, as well as the general expense of hypersonic experiments. While computational receptivity studies have been prominent in the literature, most of these prior studies have focused on discrete frequency disturbances and have neglected to consider the more continuous and broadband disturbance spectra that can be found in experiments and in flight. This work aims to expand the prior body of receptivity research by studying the response to broadband disturbances that are more reflective of realistic environmental forcing. This process involves simulating the receptivity to axisymmetric disturbances as well as some preliminary investigations of the receptivity to 3-D pulse disturbances which excite azimuthal wave modes. The axisymmetric receptivity coefficients are also used to explore further applications of the amplitude method for transition prediction. This work uses perfect gas linear stability theory (LST) and direct numerical simulation (DNS) to simulate the Mach 10 flow over 9.525 mm (Case B), 5.080 mm (Case I), and 1 mm (Case S) nose radius axisymmetric straight cones with 7-degree half-angles. Case B and Case I utilized approximately the same freestream conditions, while the unit Reynolds number for Case S is 60\% lower. The 2-D receptivity of Case B and Case I are studied using finite spherical and planar pulse disturbances in the freestream. These include freestream fast acoustic, slow acoustic, temperature, and vorticity disturbances in order to generate receptivity coefficient spectra for a wide variety of possible freestream noise sources. LST analysis predicted significant second mode growth for both Case B and Case I, with mode F being unstable for Case B and mode S being unstable for Case I. Case I was found to be more destabilizing to the second mode, as expected from the reduced nose radius. These LST results are used to validate the unsteady DNS, and to extract receptivity coefficients for the dominant second mode disturbance. The sharpest Case S is also studied using both axisymmetric planar acoustic pulses as well as azimuthally varying, 3-D acoustic pulse disturbances. Unsteady DNS for Case B and Case I show that all of the disturbances excite second mode growth and generally follow the amplification profile predicted by LST. The results for the blunter Case B show much stronger freestream noise effects than for Case I, while Case I seems to be more sensitive to extremely low frequency boundary layer modes associated with upstream disturbances originating in the entropy layer. Additionally, the blunter Case B is observed to have a much stronger supersonic mode, which is qualitiatively observed in acoustic radiation from the boundary layer disturbance wavepacket. This is attributed to the destabilized discrete mode F in Case B which is more capable than the discrete mode S of slowing and becoming supersonic relative to the meanflow. DNS and LST data are used to extract second mode receptivity coefficients and phase spectra for Case B and Case I for application to an iterative transition prediction method. The receptivity coefficients are decomposed from the total surface disturbance by renormalizing the unsteady DNS data with the LST-derived amplifcation rate. Most pulse cases saw the same spectral receptivity coefficient behavior, with peak amplitudes being at the most amplified downstream frequencies. However, the planar fast acoustic pulse in both Case I and Case B was found to excite a much more broadband disturbance profile associated with continuous mode instabilities. This likely necessitates more advanced modal decomposition methods, like the bi-orthogonal decomposition, to cleanly resolve the modes of interest. Additionally, Case I was found to be much more receptive to the temperature and vorticity pulses than Case B while the acoustic responses were fairly similar. This may be due to stronger low frequency upstream forcing that was found in Case I that is associated with entropy layer modes, and indicates differing receptivity mechanisms between the two nose bluntnesses. The receptivity cofficients for Case B and Case I are applied to a simplified 2-D implementation of Mack's amplitude method in an attempt to better approximate the transition location for those cases. Unlike the conventional $e^N$ method, the amplitude method directly estimates disturbance amplitudes in the boundary layer. This requires the use of receptivity data and freestream noise profiles along with other correlations for threshold breakdown amplitudes. The correlations for freestream noise and breakdown amplitude are taken from Marineau(AIAA Journal, 2017). While some improvement is seen over the base accuracy of standard $e^N$ method predictions, the estimated transition locations using the receptivity data from this study are found to still be significantly overpredicted. The Case I results, however, match much more closely with experimental measurements likely due to the stronger second mode. The disagreement with experiment and Marineau's results can be attributed to imprecise correlations of freestream noise and oversimplifications of the original amplitude method relations. True flight conditions will inevitably contain oblique disturbances, whether through local geometry or from the nature of freestream noise. Therefore, while the 2-D second mode disturbance has found to dominate in a large selection of hypersonic flows, consideration of 3-D disturbances is necessary to complete our view of the transition process. To accomplish this a preliminary analysis of both planar 2-D and 3-D azimuthally varying pulse simulations were also run on the small bluntness (1 mm nose radius) Case S. LST analysis of this new case shows an upstream shift in the destabilized second mode positions, as well as higher destabilized frequencies that match expectations for the smaller nose radius. While the peak growthrates were highest for Case S the reduced freestream unit Reynolds number compared to Case B and Case I led to a weaker overall amplification of the second mode in the streamwise direction, as measured by peak N-factor. Freestream fast and slow acoustic pulses were modelled using gaussian distributions in both the streamwise and azimuthal directions. Results for the 2-D pulses demonstrate strong similarities to prior results for Case B and Case I, with the planar fast acoustic pulse inducing strong broadband continuous mode variation while the slow acoustic pulse induced only second mode disturbances. The 3-D azimuthally varying pulses followed a similar pattern, as downstream excitations were primarily isolated to low wavenumber modes in the slow acoustic case. The 3-D fast acoustic pulse is found to also excite a wide range of disturbance frequencies, though excited frequency bands outside of the second mode are generally confined to lower wavenumbers. Disturbances at the second mode frequencies, however, saw little to no decay at higher wavenumbers compared to the 3-D slow acoustic case. This indicates that fast acoustic disturbances are highly capable of exciting both a broad range of disturbance wavenumbers as well as a broad range of disturbance frequencies.

A Numerical Study of 2-D Surface Roughness Effects on the Growth of Wave Modes in Hypersonic Boundary Layers

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Total Pages : 219 pages
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Book Synopsis A Numerical Study of 2-D Surface Roughness Effects on the Growth of Wave Modes in Hypersonic Boundary Layers by : Kahei Danny Fong

Download or read book A Numerical Study of 2-D Surface Roughness Effects on the Growth of Wave Modes in Hypersonic Boundary Layers written by Kahei Danny Fong and published by . This book was released on 2017 with total page 219 pages. Available in PDF, EPUB and Kindle. Book excerpt: The current understanding and research efforts on surface roughness effects in hypersonic boundary-layer flows focus, almost exclusively, on how roughness elements trip a hypersonic boundary layer to turbulence. However, there were a few reports in the literature suggesting that roughness elements in hypersonic boundary-layer flows could sometimes suppress the transition process and delay the formation of turbulent flow. These reports were not common and had not attracted much attention from the research community. Furthermore, the mechanisms of how the delay and stabilization happened were unknown. A recent study by Duan et al. showed that when 2-D roughness elements were placed downstream of the so-called synchronization point, the unstable second-mode wave in a hypersonic boundary layer was damped. Since the second-mode wave is typically the most dangerous and dominant unstable mode in a hypersonic boundary layer for sharp geometries at a zero angle of attack, this result has pointed to an explanation on how roughness elements delay transition in a hypersonic boundary layer. Such an understanding can potentially have significant practical applications for the development of passive flow control techniques to suppress hypersonic boundary-layer transition, for the purpose of aero-heating reduction. Nevertheless, the previous study was preliminary because only one particular flow condition with one fixed roughness parameter was considered. The study also lacked an examination on the mechanism of the damping effect of the second mode by roughness. Hence, the objective of the current research is to conduct an extensive investigation of the effects of 2-D roughness elements on the growth of instability waves in a hypersonic boundary layer. The goal is to provide a full physical picture of how and when 2-D roughness elements stabilize a hypersonic boundary layer. Rigorous parametric studies using numerical simulation, linear stability theory (LST), and parabolized stability equation (PSE) are performed to ensure the fidelity of the data and to study the relevant flow physics. All results unanimously confirm the conclusion that the relative location of the synchronization point with respect to the roughness element determines the roughness effect on the second mode. Namely, a roughness placed upstream of the synchronization point amplifies the unstable waves while placing a roughness downstream of the synchronization point damps the second-mode waves. The parametric study also shows that a tall roughness element within the local boundary-layer thickness results in a stronger damping effect, while the effect of the roughness width is relatively insignificant compared with the other roughness parameters. On the other hand, the fact that both LST and PSE successfully predict the damping effect only by analyzing the meanflow suggests the mechanism of the damping is by the meanflow alteration due to the existence of roughness elements, rather than new mode generation. In addition to studying the unstable waves, the drag force and heating with and without roughness have been investigated by comparing the numerical simulation data with experimental correlations. It is shown that the increase in drag force generated by the Mach wave around a roughness element in a hypersonic boundary layer is insignificant compared to the reduction of drag force by suppressing turbulent flow. The study also shows that, for a cold wall flow which is the case for practical flight applications, the Stanton number decreases as roughness elements smooth out the temperature gradient in the wall-normal direction. Based on the knowledge of roughness elements damping the second mode gained from the current study, a novel passive transition control method using judiciously placed roughness elements has been developed, and patented, during the course of this research. The main idea of the control method is that, with a given geometry and flow condition, it is possible to find the most unstable second-mode frequency that can lead to transition. And by doing a theoretical analysis such as LST, the synchronization location for the most unstable frequency can be found. Roughness elements are then strategically placed downstream of the synchronization point to damp out this dangerous second-mode wave, thus stabilizing the boundary layer and suppressing the transition process. This method is later experimentally validated in Purdue's Mach 6 quiet wind tunnel. Overall, this research has not only provided details of when and how 2-D roughness stabilizes a hypersonic boundary layer, it also has led to a successful application of numerical simulation data to the development of a new roughness-based transition delay method, which could potentially have significant contributions to the design of future generation hypersonic vehicles.

Analysis of Hypersonic Boundary Layer Second Mode Instability Over a Seven Degree Cone

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Total Pages : 84 pages
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Book Synopsis Analysis of Hypersonic Boundary Layer Second Mode Instability Over a Seven Degree Cone by : Richard Dennery (CAPT, USAF.)

Download or read book Analysis of Hypersonic Boundary Layer Second Mode Instability Over a Seven Degree Cone written by Richard Dennery (CAPT, USAF.) and published by . This book was released on 1994 with total page 84 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Analysis of Hypersonic Boundary Layer Second Mode Instability Over a 7 Deg Cone

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Total Pages : 93 pages
Book Rating : 4.:/5 (227 download)

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Book Synopsis Analysis of Hypersonic Boundary Layer Second Mode Instability Over a 7 Deg Cone by :

Download or read book Analysis of Hypersonic Boundary Layer Second Mode Instability Over a 7 Deg Cone written by and published by . This book was released on 1994 with total page 93 pages. Available in PDF, EPUB and Kindle. Book excerpt: This paper presents the results of the analysis of Mach 8.0 flow over a seven degree half-angle cone. The purpose of this analysis was to develop techniques to examine boundary layer transition at hypersonic velocities. The specific objectives were to look for second mode instability waves characteristic of the transition process and to quantify the percentage of turbulent flow. Two sets of data were used in this analysis. The first set of data was taken at several axial positions at a freestream Reynolds number 4.265 million per meter. This data was used to develop the analysis techniques. The second set of data was taken at station 35 for Reynolds numbers of 3.28, 3.94,4.92, and 6.56 million per meter. Spectral analysis was used to identify 2nd mode disturbances, if they existed. The energy associated with the disturbances was then removed from the data signal to produce a new signal. The new signal was then evaluated using conditional sampling techniques. Additional methods used to assess turbulent intermittency were histogram analysis and examination of the power spectrum of the data signal. It was determined that removal of the disturbances from the raw data signal produced a cleaner signal. However, the new signals were not amenable to conditional sampling techniques. The histogram analysis proved to be inconclusive. Examination of the power spectrum showed that a laminar flow could be identified by the presence of a strong peak corresponding to the 2nd mode disturbances, but could not be used to identify a flow as being turbulent by the absence of this peak.

Hypersonic Laminar Instability on Round Cones Near Zero Angle of Attack

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Total Pages : 25 pages
Book Rating : 4.:/5 (227 download)

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Book Synopsis Hypersonic Laminar Instability on Round Cones Near Zero Angle of Attack by :

Download or read book Hypersonic Laminar Instability on Round Cones Near Zero Angle of Attack written by and published by . This book was released on 2006 with total page 25 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Hypersonic and High Temperature Gas Dynamics

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Publisher : AIAA
ISBN 13 : 9781563474590
Total Pages : 710 pages
Book Rating : 4.4/5 (745 download)

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Book Synopsis Hypersonic and High Temperature Gas Dynamics by : John David Anderson

Download or read book Hypersonic and High Temperature Gas Dynamics written by John David Anderson and published by AIAA. This book was released on 1989 with total page 710 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is a self-contained text for those students and readers interested in learning hypersonic flow and high-temperature gas dynamics. It assumes no prior familiarity with either subject on the part of the reader. If you have never studied hypersonic and/or high-temperature gas dynamics before, and if you have never worked extensively in the area, then this book is for you. On the other hand, if you have worked and/or are working in these areas, and you want a cohesive presentation of the fundamentals, a development of important theory and techniques, a discussion of the salient results with emphasis on the physical aspects, and a presentation of modern thinking in these areas, then this book is also for you. In other words, this book is designed for two roles: 1) as an effective classroom text that can be used with ease by the instructor, and understood with ease by the student; and 2) as a viable, professional working tool for engineers, scientists, and managers who have any contact in their jobs with hypersonic and/or high-temperature flow.

Flight Stability and Automatic Control

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Publisher : WCB/McGraw-Hill
ISBN 13 : 9780071158381
Total Pages : 441 pages
Book Rating : 4.1/5 (583 download)

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Book Synopsis Flight Stability and Automatic Control by : Robert C. Nelson

Download or read book Flight Stability and Automatic Control written by Robert C. Nelson and published by WCB/McGraw-Hill. This book was released on 1998 with total page 441 pages. Available in PDF, EPUB and Kindle. Book excerpt: The second edition of Flight Stability and Automatic Control presents an organized introduction to the useful and relevant topics necessary for a flight stability and controls course. Not only is this text presented at the appropriate mathematical level, it also features standard terminology and nomenclature, along with expanded coverage of classical control theory, autopilot designs, and modern control theory. Through the use of extensive examples, problems, and historical notes, author Robert Nelson develops a concise and vital text for aircraft flight stability and control or flight dynamics courses.

Instability and Transition

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Publisher : Springer Science & Business Media
ISBN 13 : 1461234328
Total Pages : 509 pages
Book Rating : 4.4/5 (612 download)

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Book Synopsis Instability and Transition by : M.Y. Hussaini

Download or read book Instability and Transition written by M.Y. Hussaini and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 509 pages. Available in PDF, EPUB and Kindle. Book excerpt: The ability to predict and control viscous flow phenomena is becoming increasingly important in modern industrial application. The Instability and Transition Workshop at Langley was extremely important in help§ ing the scientists community to access the state of knowledge in the area of transition from laminar to turbulent flow, to identify promising future areas of research and to build future interactions between researchers worldwide working in the areas of theoretical, experimental and computational fluid and aero dynamics. The set of two volume contains panel discussions and research contribution with the following objectives: (1) expose the academic community to current technologically important issues of instability and transitions in shear flows over the entire speed range, (2) acquaint the academic community with the unique combination of theoretical, computational and experimental capabilities at LaRC and foster interaction with these facilities. (3) review current state-of-the-art and propose future directions for instability and transition research, (4) accelerate progress in elucidating basic understanding of transition phenomena and in transferring this knowledge into improved design methodologies through improved transition modeling, and (5) establish mechanism for continued interaction.

Boundary Layer Flows

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Publisher : BoD – Books on Demand
ISBN 13 : 1839681853
Total Pages : 236 pages
Book Rating : 4.8/5 (396 download)

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Book Synopsis Boundary Layer Flows by : Vallampati Ramachandra Prasad

Download or read book Boundary Layer Flows written by Vallampati Ramachandra Prasad and published by BoD – Books on Demand. This book was released on 2020-01-22 with total page 236 pages. Available in PDF, EPUB and Kindle. Book excerpt: Written by experts in the field, this book, "Boundary Layer Flows - Theory, Applications, and Numerical Methods" provides readers with the opportunity to explore its theoretical and experimental studies and their importance to the nonlinear theory of boundary layer flows, the theory of heat and mass transfer, and the dynamics of fluid. With the theory's importance for a wide variety of applications, applied mathematicians, scientists, and engineers - especially those in fluid dynamics - along with engineers of aeronautics, will undoubtedly welcome this authoritative, up-to-date book.

Low-Speed Wind Tunnel Testing

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Publisher : John Wiley & Sons
ISBN 13 : 0471557749
Total Pages : 738 pages
Book Rating : 4.4/5 (715 download)

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Book Synopsis Low-Speed Wind Tunnel Testing by : Jewel B. Barlow

Download or read book Low-Speed Wind Tunnel Testing written by Jewel B. Barlow and published by John Wiley & Sons. This book was released on 1999-02-22 with total page 738 pages. Available in PDF, EPUB and Kindle. Book excerpt: A brand-new edition of the classic guide on low-speed wind tunnel testing While great advances in theoretical and computational methods have been made in recent years, low-speed wind tunnel testing remains essential for obtaining the full range of data needed to guide detailed design decisions for many practical engineering problems. This long-awaited Third Edition of William H. Rae, Jr.'s landmark reference brings together essential information on all aspects of low-speed wind tunnel design, analysis, testing, and instrumentation in one easy-to-use resource. Written by authors who are among the most respected wind tunnel engineers in the world, this edition has been updated to address current topics and applications, and includes coverage of digital electronics, new instrumentation, video and photographic methods, pressure-sensitive paint, and liquid crystal-based measurement methods. The book is organized for quick access to topics of interest, and examines basic test techniques and objectives of modeling and testing aircraft designs in low-speed wind tunnels, as well as applications to fluid motion analysis, automobiles, marine vessels, buildings, bridges, and other structures subject to wind loading. Supplemented with real-world examples throughout, Low-Speed Wind Tunnel Testing, Third Edition is an indispensable resource for aerospace engineering students and professionals, engineers and researchers in the automotive industries, wind tunnel designers, architects, and others who need to get the most from low-speed wind tunnel technology and experiments in their work.

New Results in Numerical and Experimental Fluid Mechanics X

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Publisher : Springer
ISBN 13 : 3319272799
Total Pages : 855 pages
Book Rating : 4.3/5 (192 download)

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Book Synopsis New Results in Numerical and Experimental Fluid Mechanics X by : Andreas Dillmann

Download or read book New Results in Numerical and Experimental Fluid Mechanics X written by Andreas Dillmann and published by Springer. This book was released on 2016-03-28 with total page 855 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents contributions to the 19th biannual symposium of the German Aerospace Aerodynamics Association (STAB) and the German Society for Aeronautics and Astronautics (DGLR). The individual chapters reflect ongoing research conducted by the STAB members in the field of numerical and experimental fluid mechanics and aerodynamics, mainly for (but not limited to) aerospace applications, and cover both nationally and EC-funded projects. Special emphasis is given to collaborative research projects conducted by German scientists and engineers from universities, research-establishments and industries. By addressing a number of cutting-edge applications, together with the relevant physical and mathematics fundamentals, the book provides readers with a comprehensive overview of the current research work in the field. Though the book’s primary emphasis is on the aerospace context, it also addresses further important applications, e.g. in ground transportation and energy.

Materials

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Publisher : Butterworth-Heinemann
ISBN 13 : 0080994350
Total Pages : 899 pages
Book Rating : 4.0/5 (89 download)

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Book Synopsis Materials by : Michael F. Ashby

Download or read book Materials written by Michael F. Ashby and published by Butterworth-Heinemann. This book was released on 2013-10-09 with total page 899 pages. Available in PDF, EPUB and Kindle. Book excerpt: Materials, Third Edition, is the essential materials engineering text and resource for students developing skills and understanding of materials properties and selection for engineering applications. This new edition retains its design-led focus and strong emphasis on visual communication while expanding its inclusion of the underlying science of materials to fully meet the needs of instructors teaching an introductory course in materials. A design-led approach motivates and engages students in the study of materials science and engineering through real-life case studies and illustrative applications. Highly visual full color graphics facilitate understanding of materials concepts and properties. For instructors, a solutions manual, lecture slides, online image bank, and materials selection charts for use in class handouts or lecture presentations are available at http://textbooks.elsevier.com. The number of worked examples has been increased by 50% while the number of standard end-of-chapter exercises in the text has been doubled. Coverage of materials and the environment has been updated with a new section on Sustainability and Sustainable Technology. The text meets the curriculum needs of a wide variety of courses in the materials and design field, including introduction to materials science and engineering, engineering materials, materials selection and processing, and materials in design. Design-led approach motivates and engages students in the study of materials science and engineering through real-life case studies and illustrative applications Highly visual full color graphics facilitate understanding of materials concepts and properties Chapters on materials selection and design are integrated with chapters on materials fundamentals, enabling students to see how specific fundamentals can be important to the design process For instructors, a solutions manual, lecture slides, online image bank and materials selection charts for use in class handouts or lecture presentations are available at http://textbooks.elsevier.com Links with the Cambridge Engineering Selector (CES EduPack), the powerful materials selection software. See www.grantadesign.com for information NEW TO THIS EDITION: Text and figures have been revised and updated throughout The number of worked examples has been increased by 50% The number of standard end-of-chapter exercises in the text has been doubled Coverage of materials and the environment has been updated with a new section on Sustainability and Sustainable Technology

Applied Mechanics Reviews

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Author :
Publisher :
ISBN 13 :
Total Pages : 354 pages
Book Rating : 4.3/5 (243 download)

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Book Synopsis Applied Mechanics Reviews by :

Download or read book Applied Mechanics Reviews written by and published by . This book was released on 1993 with total page 354 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Advances in Turbulence VII

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Publisher : Springer Science & Business Media
ISBN 13 : 9401151180
Total Pages : 630 pages
Book Rating : 4.4/5 (11 download)

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Book Synopsis Advances in Turbulence VII by : Uriel Frisch

Download or read book Advances in Turbulence VII written by Uriel Frisch and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 630 pages. Available in PDF, EPUB and Kindle. Book excerpt: Advances in Turbulence VII contains an overview of the state of turbulence research with some bias towards work done in Europe. It represents an almost complete collection of the invited and contributed papers delivered at the Seventh European Turbulence Conference, sponsored by EUROMECH and ERCOFTAC and organized by the Observatoire de la Côte d'Azur. New high-Reynolds number experiments combined with new techniques of imaging, non-intrusive probing, processing and simulation provide high-quality data which put significant constraints on possible theories. For the first time, it has been shown, for a class of passive scalar problems, why dimensional analysis sometimes gives the wrong answers and how anomalous intermittency corrections can be calculated from first principles. The volume is thus geared towards specialists in the area of flow turbulence who could not attend the conference as well as anybody interested in this rapidly moving field.

Hot-wire Anemometry

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Publisher : Oxford University Press, USA
ISBN 13 :
Total Pages : 216 pages
Book Rating : 4.3/5 (91 download)

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Book Synopsis Hot-wire Anemometry by : Anthony Edward Perry

Download or read book Hot-wire Anemometry written by Anthony Edward Perry and published by Oxford University Press, USA. This book was released on 1982 with total page 216 pages. Available in PDF, EPUB and Kindle. Book excerpt: