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Measurements Of Local Heat Transfer Coefficient And Film Cooling Effectiveness In Turbine Blade Tip Geometries
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Book Synopsis Measurements of Local Heat Transfer Coefficient and Film Cooling Effectiveness in Turbine Blade Tip Geometries by :
Download or read book Measurements of Local Heat Transfer Coefficient and Film Cooling Effectiveness in Turbine Blade Tip Geometries written by and published by . This book was released on 2001 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report results from a contract tasking Imperial College of Science. Technology and Medicine as follows: The project will involve the quantification of the flow and surface characteristics of turbine blade tip cooling geometry with velocity and turbulence distributions relevant to the gas turbine designer. The experimental program will provide measurements of the film cooling adiabatic effectiveness and heat transfer coefficient in a simulated blade tip. with injection from the pressure surface side near the tip. The program will be progressive and interactive. starting with a single row of film cooling holes with injection from the pressure surface side near the tip. moving towards other representative injection configurations: slot injection on the tip surface and groove-tip geometry. The project will supply validation data for the 3D Navier-Stokes solver Glenn-HT. currently used by NASA. and it will also provide insight into the performance of advanced cooling geometry configurations. The experiments will make use of liquid crystal thermography to obtain the heat transfer data. The data acquisition method corresponds to the steady-state technique with the use of wide band liquid crystals. It requires a reduced number of experiments when compared with narrow band crystals and thermocouples, and provides a high degree of spatial resolution and reduced uncertainty level. It will be accompanied by data from small-diameter thermocouples. hot wires and pressure transducers.
Book Synopsis Local Heat Transfer and Effectiveness Measurements on Film Cooled Turbine Blade Tip Models by : Srinath Varadarajan Ekkad
Download or read book Local Heat Transfer and Effectiveness Measurements on Film Cooled Turbine Blade Tip Models written by Srinath Varadarajan Ekkad and published by . This book was released on 1991 with total page 248 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Effect of Inlet Geometry on the Turbine Blade Tip Region Heat Transfer Coefficient and Effectiveness by :
Download or read book Effect of Inlet Geometry on the Turbine Blade Tip Region Heat Transfer Coefficient and Effectiveness written by and published by . This book was released on 2002 with total page 14 pages. Available in PDF, EPUB and Kindle. Book excerpt: An experimental investigation of the local film cooling effectiveness and heat transfer coefficient downstream of a row of elongated holes in a simulated axial turbine blade tip is presented. Film cooling is needed to protect the turbine blade tip region from high heat transfer rates, especially when cooling by convection is insufficient to keep the temperature distribution of the blade within the limits required. Accurate heat transfer predictions in this region of the blade are particularly difficult given the dimensionality of the flow and the narrow passage typical of turbine blades. The effect of inlet geometry film cooling injection point and blowing ratio are examined for an injection on the blade tip itself close to the pressure surface corner. Additionally the corner radii between the pressure surface and the tip were varied. The experimental method uses the steady state liquid crystal technique. Film cooling injection provides the tip with a blanket of protection from the hot leakage flow. This extends far downstream of the holes at higher blowing ratios. Inlet curvature provides greater local film cooling effectiveness but it lacks streamwise film cooling coverage. It is important to have direct injection onto the separation bubble for greater lateral film cooling coverage.
Book Synopsis A Numerical Analysis of Heat Transfer and Effectiveness on Film Cooled Turbine Blade Tip Models by : Ali A. Ameri
Download or read book A Numerical Analysis of Heat Transfer and Effectiveness on Film Cooled Turbine Blade Tip Models written by Ali A. Ameri and published by . This book was released on 1999 with total page 14 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Author :National Aeronautics and Space Administration (NASA) Publisher :Createspace Independent Publishing Platform ISBN 13 :9781720482284 Total Pages :64 pages Book Rating :4.4/5 (822 download)
Book Synopsis Effect of Film-Hole Shape on Turbine Blade Film Cooling Performance by : National Aeronautics and Space Administration (NASA)
Download or read book Effect of Film-Hole Shape on Turbine Blade Film Cooling Performance written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-05-30 with total page 64 pages. Available in PDF, EPUB and Kindle. Book excerpt: The detailed heat transfer coefficient and film cooling effectiveness distributions as well as tile detailed coolant jet temperature profiles on the suction side of a gas turbine blade A,ere measured using a transient liquid crystal image method and a traversing cold wire and a traversing thermocouple probe, respectively. The blade has only one row of film holes near the gill hole portion on the suction side of the blade. The hole geometries studied include standard cylindrical holes and holes with diffuser shaped exit portion (i.e. fanshaped holes and laidback fanshaped holes). Tests were performed on a five-blade linear cascade in a low-speed wind tunnel. The mainstream Reynolds number based on cascade exit velocity was 5.3 x 10(exp 5). Upstream unsteady wakes were simulated using a spoke-wheel type wake generator. The wake Strouhal number was kept at 0 or 0.1. Coolant blowing ratio was varied from 0.4 to 1.2. Results show that both expanded holes have significantly improved thermal protection over the surface downstream of the ejection location, particularly at high blowing ratios. However, the expanded hole injections induce earlier boundary layer transition to turbulence and enhance heat transfer coefficients at the latter part of the blade suction surface. In general, the unsteady wake tends to reduce film cooling effectiveness.Han, J. C. and Teng, S.Glenn Research CenterHEAT TRANSFER COEFFICIENTS; COOLANTS; TEMPERATURE PROFILES; SUCTION; TURBINE BLADES; HEAT MEASUREMENT; FILM COOLING; BOUNDARY LAYER TRANSITION; CASCADE WIND TUNNELS; CYLINDRICAL BODIES; EJECTION; GAS TURBINES; HOLE DISTRIBUTION (MECHANICS); LIQUID CRYSTALS; LOW SPEED; THERMAL PROTECTION; THERMOCOUPLES; WIND TUNNELS
Book Synopsis Film Cooling and End Wall Heat Transfer in Small Turbine Blade Passages by :
Download or read book Film Cooling and End Wall Heat Transfer in Small Turbine Blade Passages written by and published by . This book was released on 1978 with total page 56 pages. Available in PDF, EPUB and Kindle. Book excerpt: Two topics have been studied related to the cooling of the end wall of a turbine passage. The first concerns the development of a method for measuring the adiabatic wall effectiveness and heat transfer coefficient of a film cooling system for protecting a surface from high heating derived from a hot compressible flow. The second concerns the measurement of the heat transfer rate distribution to a turbine cascade end wall in order to choose an appropriate film cooling system. These are related to providing the background to the final phase of the study in which the effectiveness of a film cooling system to cool a turbine end wall will be made combined with the measurement of the aerodynamic losses incurred by such a system. (Author).
Book Synopsis Measurements of Heat Transfer, Flow, and Pressures in a Simulated Turbine Blade Internal Cooling Passage by : Louis M. Russell
Download or read book Measurements of Heat Transfer, Flow, and Pressures in a Simulated Turbine Blade Internal Cooling Passage written by Louis M. Russell and published by . This book was released on 1997 with total page 30 pages. Available in PDF, EPUB and Kindle. Book excerpt: An experimental study was made to obtain quantitative information on heat transfer, flow, and pressure distribution in a branched duct test section that had several significant features of an internal cooling passage of a turbine blade. The objective of this study was to generate a set of experimental data that could be used for validation of computer codes that would be used to model internal cooling. Surface heat transfer coefficients and entrance flow conditions were measured at nominal entrance Reynolds numbers of 45 000, 335 000, and 726 000. Heat transfer data were obtained by using a steady-state technique in which an Inconel heater sheet is attached to the surface and coated with liquid crystals. Visual and quantitative flow-field data from particle image velocimetry measurements for a plane at midchannel height for a Reynolds number of 45 000 were also obtained. The flow was seeded with polystyrene particles and illuminated by a laser light sheet. Pressure distribution measurements were made both on the surface with discrete holes and in the flow field with a total pressure probe. The flow-field measurements yielded flow-field velocities at selected locations. A relatively new method, pressure sensitive paint, was also used to measure surface pressure distribution. The pressure paint data obtained at Reynolds numbers of 335 000 and 726 000 compared well with the more standard method of measuring pressures by using discrete holes.
Book Synopsis Measurement of Local Heat Transfer Coefficient and Film Cooling Effectiveness in Film Cooling Geometries by :
Download or read book Measurement of Local Heat Transfer Coefficient and Film Cooling Effectiveness in Film Cooling Geometries written by and published by . This book was released on 2000 with total page 642 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Measurement of Local Heat Transfer Coefficient and Film Cooling Effectiveness in Film Cooling Geometrics by : Connie Hong Nei Yuen
Download or read book Measurement of Local Heat Transfer Coefficient and Film Cooling Effectiveness in Film Cooling Geometrics written by Connie Hong Nei Yuen and published by . This book was released on 2000 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Film Cooling and Turbine Blade Heat Transfer by :
Download or read book Film Cooling and Turbine Blade Heat Transfer written by and published by . This book was released on 1982 with total page 262 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Experimental Study of Gas Turbine Blade Film Cooling and Heat Transfer by : Diganta P. Narzary
Download or read book Experimental Study of Gas Turbine Blade Film Cooling and Heat Transfer written by Diganta P. Narzary and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Modern gas turbine engines require higher turbine-entry gas temperature to improve their thermal efficiency and thereby their performance. A major accompanying concern is the heat-up of the turbine components which are already subject to high thermal and mechanical stresses. This heat-up can be reduced by: (i) applying thermal barrier coating (TBC) on the surface, and (ii) providing coolant to the surface by injecting secondary air discharged from the compressor. However, as the bleeding off of compressor discharge air exacts a penalty on engine performance, the cooling functions must be accomplished with the smallest possible secondary air injection. This necessitates a detailed and systematic study of the various flow and geometrical parameters that may have a bearing on the cooling pattern. In the present study, experiments were performed in three regions of a non-rotating gas turbine blade cascade: blade platform, blade span, and blade tip. The blade platform and blade span studies were carried out on a high pressure turbine rotor blade cascade in medium flow conditions. Film-cooling effectiveness or degree of cooling was assessed in terms of cooling hole geometry, blowing ratio, freestream turbulence, coolant-to-mainstream density ratio, purge flow rate, upstream vortex for blade platform cooling and blowing ratio, and upstream vortex for blade span cooling. The blade tip study was performed in a blow-down flow loop in a transonic flow environment. The degree of cooling was assessed in terms of blowing ratio and tip clearance. Limited heat transfer coefficient measurements were also carried out. Mainstream pressure loss was also measured for blade platform and blade tip film-cooling with the help of pitot-static probes. The pressure sensitive paint (PSP) and temperature sensitive paint (TSP) techniques were used for measuring film-cooling effectiveness whereas for heat transfer coefficient measurement, temperature sensitive paint (TSP) technique was employed. Results indicated that the blade platform cooling requires a combination of upstream purge flow and downstream discrete film-cooling holes to cool the entire platform. The shaped cooling holes provided wider film coverage and higher film-cooling effectiveness than the cylindrical holes while also creating lesser mainstream pressure losses. Higher coolant-to-mainstream density ratio resulted in higher effectiveness levels from the cooling holes. On the blade span, at any given blowing ratio, the suction side showed better coolant coverage than the pressure side even though the former had two fewer rows of holes. Film-cooling effectiveness increased with blowing ratio on both sides of the blade. Whereas the pressure side effectiveness continued to increase with blowing ratio, the increase in suction side effectiveness slowed down at higher blowing ratios (M=0.9 and 1.2). Upstream wake had a detrimental effect on film coverage. 0% and 25% wake phase positions significantly decreased film-cooling effectiveness magnitude. Comparison between the compound shaped hole and the compound cylindrical hole design showed higher effectiveness values for shaped holes on the suction side. The cylindrical holes performed marginally better in the curved portion of the pressure side. Finally, the concept tip proved to be better than the baseline tip in terms of reducing mainstream flow leakage and mainstream pressure loss. The film-cooling effectiveness on the concept blade increased with increasing blowing ratio and tip gap. However, the film-coverage on the leading tip portion was almost negligible.
Book Synopsis Effect of Blade-tip Crossover Passages on Natural-convection Water-cooling of Gas-turbine Blades by : Charles F. Zalabak
Download or read book Effect of Blade-tip Crossover Passages on Natural-convection Water-cooling of Gas-turbine Blades written by Charles F. Zalabak and published by . This book was released on 1956 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt: A water-cooled turbine was fabricated and tested to determine the effect of a connecting passage at the turbine rotor blade tip between a radial coolant passage 0.10 inch in diameter (length-diameter ratio = 25.5) and radial coolant passages in the legnth-diameter range of 5.1 to 20.4. Coolant flow through the connecting passage is induced by free-convection forces in the radial passages.
Author :National Aeronautics and Space Administration (NASA) Publisher :Createspace Independent Publishing Platform ISBN 13 :9781721189052 Total Pages :26 pages Book Rating :4.1/5 (89 download)
Book Synopsis A Numerical Analysis of Heat Transfer and Effectiveness on Film Cooled Turbine Blade Tip Models by : National Aeronautics and Space Administration (NASA)
Download or read book A Numerical Analysis of Heat Transfer and Effectiveness on Film Cooled Turbine Blade Tip Models written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-06-15 with total page 26 pages. Available in PDF, EPUB and Kindle. Book excerpt: A computational study has been performed to predict the distribution of convective heat transfer coefficient on a simulated blade tip with cooling holes. The purpose of the examination was to assess the ability of a three-dimensional Reynolds-averaged Navier-Stokes solver to predict the rate of tip heat transfer and the distribution of cooling effectiveness. To this end, the simulation of tip clearance flow with blowing of Kim and Metzger was used. The agreement of the computed effectiveness with the data was quite good. The agreement with the heat transfer coefficient was not as good but improved away from the cooling holes. Numerical flow visualization showed that the uniformity of wetting of the surface by the film cooling jet is helped by the reverse flow due to edge separation of the main flow. Ameri, A. A. and Rigby, D. L. Glenn Research Center NASA/CR-1999-209165, NAS 1.26:209165, E-11756
Book Synopsis Measurement and Analysis of Gas Turbine Blade Tip Heat Transfer and Film Cooling by : Jae Su Kwak
Download or read book Measurement and Analysis of Gas Turbine Blade Tip Heat Transfer and Film Cooling written by Jae Su Kwak and published by . This book was released on 2002 with total page 266 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Film Cooling, Heat Transfer and Aerodynamic Measurements in a Three Stage Research Gas Turbine by : Arun Suryanarayanan
Download or read book Film Cooling, Heat Transfer and Aerodynamic Measurements in a Three Stage Research Gas Turbine written by Arun Suryanarayanan and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The existing 3-stage turbine research facility at the Turbomachinery Performance and Flow Research Laboratory (TPFL), Texas A and M University, is re-designed and newly installed to enable coolant gas injection on the first stage rotor platform to study the effects of rotation on film cooling and heat transfer. Pressure and temperature sensitive paint techniques are used to measure film cooling effectiveness and heat transfer on the rotor platform respectively. Experiments are conducted at three turbine rotational speeds namely, 2400rpm, 2550rpm and 3000rpm. Interstage aerodynamic measurements with miniature five hole probes are also acquired at these speeds. The aerodynamic data characterizes the flow along the first stage rotor exit, second stage stator exit and second stage rotor exit. For each rotor speed, film cooling effectiveness is determined on the first stage rotor platform for upstream stator-rotor gap ejection, downstream discrete hole ejection and a combination of upstream gap and downstream hole ejection. Upstream coolant ejection experiments are conducted for coolant to mainstream mass flow ratios of MFR=0.5%, 1.0%, 1.5% and 2.0% and downstream discrete hole injection tests corresponding to average hole blowing ratios of M = 0.5, 0.75, 1.0, 1.25, 1.5, 1.75 and 2.0 for each turbine speed. To provide a complete picture of hub cooling under rotating conditions, experiments with simultaneous injection of coolant gas through upstream and downstream injection are conducted for an of MFR=1% and Mholes=0.75, 1.0 and 1.25 for the three turbine speeds. Heat transfer coefficients are determined on the rotor platform for similar upstream and downstream coolant injection. Rotation is found to significantly affect the distribution of coolant on the platform. The measured effectiveness magnitudes are lower than that obtained with numerical simulations. Coolant streams from both upstream and downstream injection orient themselves towards the blade suction side. Passage vortex cuts-off the coolant film for the lower MFR for upstream injection. As the MFR increases, the passage vortex effects are diminished. Effectiveness was maximum when Mholes was closer to one as the coolant ejection velocity is approximately equal to the mainstream relative velocity for this blowing ratio. Heat transfer coefficient and film cooling effectiveness increase with increasing rotational speed for upstream rotor stator gap injection while for downstream hole injection the maximum effectiveness and heat transfer coefficients occur at the reference speed of 2550rpm.
Book Synopsis Turbine Blade Tip Film Cooling Measurements by : Dean Andrew Ward
Download or read book Turbine Blade Tip Film Cooling Measurements written by Dean Andrew Ward and published by . This book was released on 1992 with total page 332 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Survey of Advantages and Problems Associated with Transpiration Cooling and Film Cooling of Gas-turbine Blades by : Ernst Rudolf Georg Eckert
Download or read book Survey of Advantages and Problems Associated with Transpiration Cooling and Film Cooling of Gas-turbine Blades written by Ernst Rudolf Georg Eckert and published by . This book was released on 1951 with total page 44 pages. Available in PDF, EPUB and Kindle. Book excerpt: Summary: Transpiration and film cooling promise to be effective methods of cooling gas-turbine blades; consequently, analytical and experimental investigations are being conducted to obtain a better understanding of these processes. This report serves as an introduction to these cooling methods, explains the physical processes, and surveys the information available for predicting blade temperatures and heat-transfer rates. In addition, the difficulties encountered in obtaining a uniform blade temperature are discussed, and the possibilities of correcting these difficulties are indicated. Air is the only coolant considered in the application of these cooling methods.