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Ablative Erosion Model For The M256 M829e3 Gun System
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Book Synopsis Ablative Erosion Model for the M256/M829E3 Gun System by :
Download or read book Ablative Erosion Model for the M256/M829E3 Gun System written by and published by . This book was released on 2001 with total page 26 pages. Available in PDF, EPUB and Kindle. Book excerpt: A combination of bore-protecting ablative and bore-coating technologies is necessary to reduce erosion for current and future high-performance gun systems. Our cannon coating erosion model developed in 1996 is fully capable of incorporating the added complexity of bore-protecting ablatives. Both nonablative and ablative results from this model have been published for a number of important Army and Navy gun systems with bore coatings. This erosion model is guided and calibrated and correlates very well with substantial gun system firing data and subsequent laboratory analysis of fired specimens. Additionally, the model uses measured ablative flow and thermal decomposition data to determine the ablative mechanisms and guide/calibrate ablative modeling. The purpose of this report is to show how our ablative model incorporates into our overall cannon coating erosion code by using the experimental ablative M256/MS29E3 gun system as an illustrative example. Although we do not have authority to release the composition and processing of this proprietary ablative paste, we do have authority to release its general thermal decomposition, flow characteristics, and ablative mechanism data. These decomposition, flow, and ablative mechanism data are used by the thermochemical, boundary layer, and thermal and erosion modeling codes to include the effect of the ablative paste and its associated thermal decomposition products. Experimental ablative M829E3 rounds-to-erosion condemnation at the peak eroded 1.6-meter from the rear face of the tube position determines this gun system's predicted erosion life. At that position, the respective 49 deg C, 21 deg C, and -32 deg C round-conditioning temperature cases achieve predicted erosion condemnation at approximately 240, 390, and 350 rounds.
Book Synopsis Erosion Modeling of the 120-MM M256/M829A2 Gun System by :
Download or read book Erosion Modeling of the 120-MM M256/M829A2 Gun System written by and published by . This book was released on 1997 with total page 30 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Benet Laboratories/Software and Engineering Associates, Inc. (SEA) gun barrel erosion modeling and design code predicts wall degradation due to transformations, chemical reactions, and cracking coupled with pure mechanical erosion for the 120-man M256/MS29A2 gun system for ambient temperature-conditioned rounds. The A723 steel and 0.005-inch high contraction (HC) chromium plated/A723 steel wall materials are evaluated for erosion. This complex computer analysis is based on rigorously evaluated scientific theory that has been validated in the rocket community over the last forty years. Our gun erosion analysis includes the standard interior ballistics gun code (XNOVAKTC), the standard nonideal gas-wall thermochemical rocket code modified for guns (CCET). the standard mass addition boundary layer rocket code modified for guns (MABL), and the standard wall material ablation conduction erosion rocket code modified for guns (MACE). In addition, bore subsurface metallographic analysis and projectile-bore finite element analysis (ABAQUS) are considered. Our overall analysis provides wall material erosion predictions and comparisons of ablation, conduction, and erosion profiles as a function of time, travel (customer-selected 27. 61, 86, 130, and 201 inches from the rear face of the tube), and number of rounds to barrel condemnation. The 120-mm M256/M829A2 gun system prediction, with significant numbers of M829A2 rounds, agrees well with the wear and erosion pattern of retired M256 gun barrels.
Book Synopsis Comprehensive Erosion Model for the 120-MM M256/M829A2 Gun System by :
Download or read book Comprehensive Erosion Model for the 120-MM M256/M829A2 Gun System written by and published by . This book was released on 1998 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Most 120-mm M256 guns firing the M829 round as their "honest" kinetic energy round have been condemned because of fatigue. Despite this fact, it is still important to determine the erosion life of the M829 round, since M256 guns that have fired the most recent kinetic energy rounds (M829A1, M829A2) rely on the M829 round for baseline dispersion testing of that gun. Today this generally results in M256 guns that having an equal mix of M829 and M829A2 rounds, thus necessitating the consideration of M829 round effects for any erosion analysis. Variability exists for M256 guns with M829 rounds depending on round count, round type, round-conditioning temperature, and their order. Distinctive erosion patterns and mechanisms are emerging as our gun erosion database increases for in-service and out-of-service 120-mm M256 tubes with M829 rounds. Our M256/M829 gun system erosion model-with its interior ballistics, thermochemistry, and boundary layer components-is constantly being guided and refined by the erosion and materials analysis data from fired gun tubes. A recent refinement includes improvement of the gun steel subsurface exposure model due to high quality, difficult to obtain data from in-service M256 tubes. Other recent refinements to the boundary layer heat transfer model are based on thermal data from M256 tubes. These refinements include the improvement/incorporation of case gas cooling effects, turbulent gas mixing/heating effects, and a very minor contribution from forcing cone-induced vena contracta cooling effects. These latter refinements are calibrated away from crack walls by positional thermal wall repacking depth, thermal wall transformation depth, and thermocouple data.
Book Synopsis 35th AIAA Thermophysics Conference by :
Download or read book 35th AIAA Thermophysics Conference written by and published by . This book was released on 2001 with total page 646 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Updated Erosion Modeling Predictions for the M829E3 Round by :
Download or read book Updated Erosion Modeling Predictions for the M829E3 Round written by and published by . This book was released on 2002 with total page 23 pages. Available in PDF, EPUB and Kindle. Book excerpt: Erosion modeling predictions are given for the current M829E3 round configuration and weighted averages per temperature for the computer correction factor(CCF). Our gun erosion model was developed through a ten-year joint partnership with Software and Engineering Associates, Inc., Carson City, NV. These predictions are based on recent cannon characterization data. These latest predictions include significant changes in propellant configuration and projectile weight that were made to the current M829E3 configuration compared to our initially presented M829E3 modeling predictions two years ago. For the last two years, additional nonablative M829E3 erosion modeling predictions have not been conducted or presented. This was due to a diversion of erosion modeling resources toward ablative M829E3 erosion predictions and erosion predictions related to the selection of six M256 cannons for M829E3-related fatigue testing. For the current M829E3 configuration, these changes in gas pressure. gas temperature, gas velocity, and increased projectile weight collectively contributed to a predicted increase in M256 cannon erosion life compared to our initially presented M829E3 modeling effort. In addition, the current set of M829E3 weighted averages per temperature for CCF from Fort Knox (19% hot 49 degrees C/120 degrees F, 64% basic 21 degrees C/70 degrees F, 16% cold -7 degrees C/20 degrees F, and 1% severe -32 degrees C/-25 degrees F) collectively contributed to a further predicted increase in M256 cannon erosion life compared to the two-year-old set of weighted averages per temperature (33% hot, 33% basic, 0% cold, and 33% severe). For the current predictions, the peak eroded cannon axial position remains at approximately 60 inches from the rear face of the tube plus or 6 inches; and this position dictates the erosion life of the cannon.
Book Synopsis Fatigue and Fracture Mechanics by : Walter G. Reuter
Download or read book Fatigue and Fracture Mechanics written by Walter G. Reuter and published by ASTM International. This book was released on 2002-12-31 with total page 778 pages. Available in PDF, EPUB and Kindle. Book excerpt: Covering the whole of Asia and the Pacific region, this text provides both an analytic overview and specific data for each of the 60 countries. Introductory chapters cover regional issues, including: a regional review with the year's trends, developments and key events' analysis of the threat of terrorism in the region; the effects of deflation on the economy; the water crisis and its impact on the poor; and the successes and failures of micro-credit in the region.
Book Synopsis Cannon Coating Erosion Modeling Achievements by :
Download or read book Cannon Coating Erosion Modeling Achievements written by and published by . This book was released on 2001 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Our repeatedly verified erosion theories are derived from many years of conducting the Army's mission of characterizing a broad spectrum of fired and eroded cannons. Based on these characterizations, we chronicle the establishment, development, achievement, and advancement of the first practical cannon and cannon coating/ablative erosion models for large and medium caliber gun systems. The U.S. Army Research Laboratory's subsequent confirmation and adoption of our cannon and cannon coating/ablative erosion theories and models is also chronicled. This new method, in conjunction with limited-scale firings, has greatly increased the Army's technical capability and provides a reliable and cost effective means of comprehensively studying the erosion of coated cannon bores that previously required costly full-scale firings. Our comprehensive cannon erosion theories, models, and predictions have been widely embraced by Army and Navy program managers, saving them millions of dollars, and having a far-reaching impact on gun system design, optimization, and testing. Initially we discuss our early erosion theories and limited erosion models. Then we continue in chronological order with a discussion of our first practical cannon erosion model with an advanced artillery gun system example. Next, we discuss the extension of this initial model to our first practical cannon coating/ablative erosion model with an advanced medium caliber gun system example. We then discuss the adaptation of our cannon coating/ablative erosion model to advanced tank gun systems. Finally, we conclude with a description of our recent erosion modeling efforts. The following is a description of the methodology that has been established, developed, and applied to address the current Army problem of cannon bore erosion on advanced gun systems.
Book Synopsis Modeling of Erosive Combustion Products Affecting the 120-MM M256/M829A2 Gun System by :
Download or read book Modeling of Erosive Combustion Products Affecting the 120-MM M256/M829A2 Gun System written by and published by . This book was released on 1997 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The MACE gun barrel erosion code is used to thermochemically model erosive combustion products affecting the 0.005-inch high contraction (HC) chromium plated A723 steel 120-mm M256/ambient temperature-conditioned M829A2 gun system for a single-round firing scenario. The HC chromium plate, the subsurface A723 steel substrate at HC chromium crack bases, and bare A723 steel are evaluated. This gun erosion analysis includes the standard interior ballistics gun code (XNOVAKTC), the standard nonideal gas-wall thermochemical rocket code modified for guns (CCET), the standard mass addition boundary layer rocket code modified for guns (MABL), and the standard wall material ablation conduction code modified for guns (MACE). Specifically, this new variation of the gun erosion analysis uses MACE wall temperatures as a function of time/position/depth, as well as their associated gas pressures as a function of time/position to thermochemically compute differences in combustion products for the various reacting and nonreacting walls allowing erosive combustion products to be identified. Identification of erosive combustion products by comparative modeling between proposed and present propellant formulations or between a propellant formulation with and without additives may benefit current U.S. Army/Navy programs that attempt to lower propellant flame temperature and/or propellant erosion. Carbon dioxide, water, and carbon monoxide are the identified erosive combustion products for this gun system.
Book Synopsis Shot-By-Shot Erosion Modeling of Retired 120mm M256 Gun Tube #1988 by :
Download or read book Shot-By-Shot Erosion Modeling of Retired 120mm M256 Gun Tube #1988 written by and published by . This book was released on 1998 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: As our gun erosion database increases for in-service and out-of-service 120-mm M256 tubes with M829Ax series rounds, distinct erosion patterns and mechanisms are emerging. Variability exists for M256 guns with M829Ax series rounds depending on round count, round type, round-conditioning temperature, and their order. Our M256/M829Ax gun system erosion model - with its interior ballistics, thermochemistry, and boundary layer components - is constantly being guided and refined by the erosion and materials analysis data from fired gun tubes. A recent refinement includes the improvement of the gun steel subsurface exposure model due to high quality, difficult to obtain data from in-service M256 tubes. Other recent refinements to the boundary layer heat transfer model are based on thermal data from M256 tubes. These refinements include the improvement/incorporation of case gas cooling effects, turbulent gas mixing/heating effects, and a very minor contribution from forcing cone-induced vena contracta cooling effects. These latter refinements are calibrated away from crack walls by positional thermal wall repacking depth, thermal wall transformation depth, and thermocouple data. A comprehensive gun erosion model is described for the 120-mm M256 gun with its M829Ax series rounds. In addition, a detailed shot-by-shot erosion modeling prediction is escribed for retired 120-mm M256 gun tube serial #1988. For this gun tube, the erosion prediction includes the two types of rounds fired, 829 and M829A2, and their three round-conditioning temperatures, hot, ambient, and cold. The gun erosion mechanism consists of heat checking the inert chromium plate, subsequent interfacial degradation of the subsurface gun steel substrate at the chromium crack bases, then chromium platelet spalling, and subsequent bare gun steel gas wash. This gun erosion model correctly calculates and predicts that the worst eroded region is at 1.2 to 2.4 meters from the rear face of the tube.
Book Synopsis Thermochemical Erosion Modeling of the 25mm M242/M791 Gun System by :
Download or read book Thermochemical Erosion Modeling of the 25mm M242/M791 Gun System written by and published by . This book was released on 1997 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The MACE gun barrel thermochemical erosion modeling code addresses wall degradations due to transformations, chemical reactions, and cracking coupled with pure mechanical erosion for the 25-mm M242/M791 gun system. This predictive tool provides gun system design information that is otherwise impractical. The nitrided A723 and 0.002-inch plated chromium/A723 wall materials are evaluated for erosion using the M242 Cycle A firing scenario. This complex computer analysis is based on rigorously evaluated scientific theory that has been validated in the rocket community over the last forty years. Our gun erosion analysis includes the standard interior ballistics gun code (XNOVAKTC), the standard nonideal gas-wall thermochemical rocket code modified for guns (CCET), the standard mass addition boundary layer rocket code modified for guns (MABL), and the standard wall material ablation conduction erosion rocket code modified for guns (MACE). This analysis provides wall material erosion predictions and comparisons (ablation, conduction, and erosion profiles) as a function of time, travel (customer-selected 6-inch, 12-inch, 30-inch), and number of rounds to barrel condemnation. These M242/M791 gun system predictions agree well with the standard wall heat transfer/temperature profile code (FDHEAT) and actual measured gun system erosion data.
Book Synopsis A Numerical Method for Predicting Thermal Erosion in Gun Tubes by :
Download or read book A Numerical Method for Predicting Thermal Erosion in Gun Tubes written by and published by . This book was released on 1996 with total page 40 pages. Available in PDF, EPUB and Kindle. Book excerpt: A numerical model for predicting the thermal erosion on the in-bore surface of a gun tube due to high convective heating is presented. The model is based on a unidimensional implicit numerical solution of the heat conduction equation with an ablation boundary condition. The ablation boundary condition models the heat transfer at the melt interface and allows the ablation rate of the surface to be predicted. The model has been validated against previous numerical and analytical results for related model problems. Application of the numerical model has been made to predict the erosion on the M256 cannon firing the M829Al projectile. The predicted ablation rates are within the observed erosion rates for normal erosion on the M256 cannon.
Download or read book Fatigue and Fracture Mechanics written by and published by . This book was released on 2001 with total page 796 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Thermochemical Erosion Modeling of Original M242/M919 Gun System by :
Download or read book Thermochemical Erosion Modeling of Original M242/M919 Gun System written by and published by . This book was released on 1997 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt: This MACE gun barrel thermochemical erosion modeling code addresses wall degradations due to transformations, chemical reactions, and cracking coupled with pure mechanical erosion for the original M242/M919 gun system. This predictive tool provides gun system design information that is otherwise impractical. The A723, 0.002-inch plated chromium/A723, and 0.002-inch sputtered tantalum/A723 wall materials are evaluated for erosion using the M242 Cycle A firing scenario. This complex computer analysis is based on rigorously evaluated scientific theory that has been validated in the rocket community over the last forty years. Our gun erosion analysis includes the standard interior ballistics gun code (XNOVAKTC), the standard nonideal gas-wall thermochemical rocket code modified for guns (CCET), the standard mass addition boundary layer rocket code modified for guns (MABL), and the standard wall material ablation conduction erosion rocket code modified for guns (MACE). This analysis provides wall material erosion predictions and comparisons (ablation, conduction, and erosion profiles) as a function of time, travel (customer-selected 6-inch, 12-inch, 30-inch), and number of rounds to barrel condemnation. These original M242/M919 gun system predictions agree well with the standard wall heat transfer/ temperature profile code (FDHEAT) and actual measured gun system erosion data.
Book Synopsis Shot-by-shot Erosion Modeling of Retired 120mm M256 Gun Tube Number 1988 by : Samuel Sopok
Download or read book Shot-by-shot Erosion Modeling of Retired 120mm M256 Gun Tube Number 1988 written by Samuel Sopok and published by . This book was released on 1998 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis LC-CR Plated Crusader Gun System Erosion Modeling by : S. Sopok
Download or read book LC-CR Plated Crusader Gun System Erosion Modeling written by S. Sopok and published by . This book was released on 2003 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Chemical Abstracts written by and published by . This book was released on 2002 with total page 2626 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Thermomechanical Erosion Modeling of the 25mm M242/M791 Gun System by : Samuel Sopok
Download or read book Thermomechanical Erosion Modeling of the 25mm M242/M791 Gun System written by Samuel Sopok and published by . This book was released on 1997 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
