Download or read book Reports on Gun Barrel Erosion written by United States. Army. Ordnance Corps and published by . This book was released on 1952 with total page 274 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Erosion in Large Gun Barrels written by and published by . This book was released on 1975 with total page 57 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Erosion in Large Gun Barrels written by and published by National Academies. This book was released on 1975-01-15 with total page 72 pages. Available in PDF, EPUB and Kindle. Book excerpt: Confronted with problems associated with the continual upgrading of field guns, reducing the number of different items in supply and lowering overall costs, the Department of the Army has need for improved methods of reducing erosion and extending the wear life of long range cannon. The National Materials Advisory Board was asked to consider all facets of this need and to make recommendations. Erosion in Large Gun Barrels assesses the nature of the bore erosion problem; identifies fruitful areas of research; assesses the state of technology of materials and methods in areas which may become significant to gun tubes of improved performance; and suggests experimental techniques, devices, and instruments and methods of reducing data to enhance the continuing coordination of the activities of the three Services.
Download or read book Erosion in Large Gun Barrels written by NATIONAL MATERIALS ADVISORY BOARD (NAS-NAE) WASHINGTON D C. and published by . This book was released on 1975 with total page 67 pages. Available in PDF, EPUB and Kindle. Book excerpt: The erosion of gun tubes is a very complex interdisciplinary problem involving several branches of engineering and science. Several mechanisms are responsible for this limitation to gun tube life, some of which are of thermal origin, some are mechanical and some chemical. The exact combination of these mechanisms will depend upon the following components of the gun system. (1) The gun barrel system; (2) The projectile system; (3) The charge assembly; (4) Wear reducing additives in the propellant; (5) Firing conditions. After reviewing the history of gun barrel erosion from these several points of view, possible mechanisms are discussed. Several other fields of engineering endeavors that are limited by severe wear problems are reviewed for possible sources of technology transfer. The report concludes by suggesting long and short range programs, including a number of specific ideas that should be evaluated.
Download or read book Experimental Plating of Gun Bores to Retard Erosion written by Vernon A. Lamb and published by . This book was released on 1960 with total page 248 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Erosion in Gun Barrels written by DEFENSE DOCUMENTATION CENTER ALEXANDRIA VA. and published by . This book was released on 1973 with total page 68 pages. Available in PDF, EPUB and Kindle. Book excerpt: The bibliography is a compilation of references pertaining to Erosion in Gun Barrels. Corporate Author-Monitoring Agency, Subject, Title, Personal Author, Contract, and Report Number indexes are included. (Author).
Download or read book A New Additive for Reducing Gun Barrel Erosion written by Jean-Paul Picard and published by . This book was released on 1968 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Barrel Erosion Rate of a 60mm Gun written by George Samos and published by . This book was released on 1978 with total page 52 pages. Available in PDF, EPUB and Kindle. Book excerpt: The 60mm gun, BG3, used in the Anti-Armor Automatic Cannon Technology Program (AAAC), fired 69 rounds with various wear-reducing additives. The wear rate per round measured on the vertical land diameter 20.75 inches (527mm) from the rear face of the tube was 0.7-0.8 mil/rd (0.018-0.020 mm/rd) for each additive configuration. In order to test the hypothesis that the various additives were not affecting the wear rate of the cannon, ten rounds were fired without any additives. The wear rate increased to 2.0 mils/rd (0.051 mm/rd). The ten round group was followed by a five round series with additive which showed the same low wear rate seen in the first 69 rounds. The wear profile of the MC-AAAC cannon is similar to the wear profile of the 105mm M68 tank cannon firing rounds without additive. However, the MC-AAAC did not have a secondary wear peak. The wear rate without additive was predicted reasonably well by both the Frankle and Smith-O'Brasky models. The Smith-O'Brasky model, which has a correction to the propellant flame temperature to account for the presence of the wear-reducing additive, correctly predicted the wear rate of the MC-AAAC with the additive. (Author).
Download or read book Gas Chemistry Effects on Gun Barrel Erosion A Shock Tube Gun Investigation written by and published by . This book was released on 1982 with total page 99 pages. Available in PDF, EPUB and Kindle. Book excerpt: The subject program is part of a continuing effort to identify distinct mechanisms that contribute to gun barrel wear and erosion. The thermochemical effects of altering the CO/CO2 ratio of a propellant gas in a gun tube was the main topic for investigation in this program. Experiments were conducted in the Shock Tube Gun (STG), a ballistic compressor, designed and developed by Calspan Corporation. This facility can compress mixtures of pure gases to simulate propellant gas flow conditions and cycle times experienced in large caliber guns. Tests were conducted with mixture ratios of carbon monoxide and carbon dioxide that characterize the normal range of CO/CO2 ratios found in propellant gas, i.e., 2.0 to 8.1. Progressive substitution of carbon monoxide for nitrogen in the mix quantified erosion as a function of increasing Co concentration or CO/CO2 ratio. Subsequent tests were conducted with gas mixtures containing double the amount of carbon monoxide and carbon dioxide but with the same effect CO/CO2 ratio, to measure erosion as a function of absolute reactant concentration for the two gas species. The basic chemical effect was observed to be a shift in the erosion threshold to less severe convective heating conditions in response to increasing the CO/CO2 ratio above a value of 5.6. The magnitude of the shift appeared to be directly proportional to the absolute concentrations of the two reactant gases. Variation of both CO/CO2 ratio and absolute amounts of the two gases resulted in distinct changes in specimen surface characteristics, both at near threshold and above threshold flow conditions.
Download or read book Orgies Continentales written by and published by . This book was released on 1904 with total page 148 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Physicochemical Aspects of Gun Barrel Erosion and Its Control written by and published by . This book was released on 1975 with total page 26 pages. Available in PDF, EPUB and Kindle. Book excerpt: Gun tube erosion can be defined as the bore surface damage and bore enlargement caused by firing, which can lead to loss in accuracy and the effectiveness of the weapon. It is one of the two major factors on the basis of which gun tubes are condemned; the other factor being fatigue life, Erosion is a complex phenomenon resulting from the interaction of propellant gases and the projectile with the surface of the bore. The bore surface is exposed for a short time to temperature approaching the melting point of steel, pressures as high as 50,000 psi, reactive atmosphere composed of CO, CO2, H2O, H2, N2, and numerous other identified and unidentified constituents. Superimposed on these conditions are the high velocity of gases and swaging action of the projectile rotating band. It is the objective of this presentation to review the physicochemical processes involved in erosion and indicate some critical areas which need further investigation. Also, various efforts to control erosion in barrels will be briefly discussed.
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 0 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.
Download or read book Unified Computer Model for Predicting Thermochemical Erosion in Gun Barrels written by and published by . This book was released on 1995 with total page 69 pages. Available in PDF, EPUB and Kindle. Book excerpt: The first known gun barrel thermochemical erosion modeling code is presented. This modeling code provides the necessary missing element needed for developing a generalized gun barrel erosion modeling code that can provide analysis and design information that is unattainable by experiment alone. At the current stage of code development, single-shot comparisons can be made of either the same gun wall material for different rounds or different gun wall materials for the same round. This complex computer analysis is based on rigorous scientific thermochemical erosion considerations that have been validated in the reentry nosetip and rocket nozzle community over the last forty years. The 115-mm M2O3 Unicannon system example is used to illustrate the five module analyses for chromium and gun steel wall materials for the same round. The first two modules include the standard gun community interior ballistics (XNOVA/CtC) and nonideal gas thermochemical equilibrium (BLAKE) codes. The last three modules, significantly modified for gun barrels, include the standard rocket community mass addition boundary layer (rDK/MABL). gas-wall chemistry (rDK/oDE). and wall material ablation conduction erosion (MACE) codes. These five module analyses provide recession, temperature, and heat flux profiles for each material as a function of time and axial position. In addition, this output can he coupled to FEA cracking codes. At the peak heat load axial position, predicted single-shot thermochemical wall erosion showed uncracked gun steel eroded by a factor of one hundred million more than uncracked chromium. For chromium plated gun steel, with its associated crack profile, it appears that gun steel ablation at the chromium cracks leaves unsupported chromium, which is subsequently removed by the high-speed gas flow. (AN).
Download or read book Study of Heat Transfer and Erosion in Gun Barrels written by and published by . This book was released on 1973 with total page 253 pages. Available in PDF, EPUB and Kindle. Book excerpt: This study models the combustion, solid propellant movement, gas dynamics, projectile dynamics, transient boundary layer, heat transfer, and barrel metal temperatures in a gun barrel. This is accomplished by rigorous development of the coupled partial differential equations and carrying out a detailed numerical solution to these equations. Comparison of barrel temperature solutions to experimental data is shown. Erosion mechanisms are discussed in the light of these solutions. This model is then used to study hypotheses concerning the heat transfer, temperature, and erosion effects of submicron size solid particle additives (TiO2) to gun propellants. A mechanism not previously studied offers excellent theoretical results in explaining the reduced erosion.
Download or read book U S Government Research Development Reports written by and published by . This book was released on 1968 with total page 168 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Wear Reducing Additives written by and published by . This book was released on 2002 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt: An investigation into developing better additives for reducing gun barrel erosion was initiated by this laboratory. The investigation was prompted by the higher energy/density propellant formulations currently under development because these new propellants possibly could exacerbate gun barrel erosion. This report is a progress report that describes the initial results obtained with the U.S. Army Armament Research, Development and Engineering Center's, Picatinny Arsenal, New Jersey erosion test fixture. Some erosion mechanisms and proposed ways to reduce or interfere with them are discussed. Three candidates were selected: K2CO3, CaCO3, and ZnCO3 and compared with the customary wear additive, TiO2. Based on the data, it was concluded that all selected candidates reduced wear caused by both M3O and JA2 propellants, but K2CO3 was ranked as most effective. The additives were also dispersed in silicone oil to form pastes. Five samples of K2CO3 paste was loaded into an experimental obturator design and test fired in a 155-mm gun. The resulting 4% decrease in heat flux suggested that paste loaded obturators may be a feasible method to reduce gun barrel wear, but further investigation is necessary to verify this assertion.
Download or read book Modeling of Gun Barrel Surface Erosion written by and published by . This book was released on 1996 with total page 51 pages. Available in PDF, EPUB and Kindle. Book excerpt: Results and interpretations of numerical simulations of some dominant processes influencing gun barrel propellant combustion and flow-induced erosion are presented. Results include modeled influences of erosion reduction techniques such as solid additives, vapor phase chemical modifications, and alteration of surface solid composition through use of thin coatings. Precedents and historical perspective are provided with predictions from traditional interior ballistics compared to computer simulations. Accelerating reactive combustion flow, multiphase and multicomponent transport, flow-to-surface thermal/momentum/phase change/gas-surface chemical exchanges, surface and micro-depth subsurface heating/stress/composition evolution and their roles in inducing surface cracking, spall, ablation, melting, and vaporization are considered. Recognition is given to cyclic effects of previous firing history on material preconditioning. Current perspective and outlook for future are based on results of a US Army-LLNL erosion research program covering 7 y in late 1970s. This is supplemented by more recent research on hypervelocity electromagnetic projectile launchers.
