WorldCat Identities

Horst, Albert W.

Overview
Works: 33 works in 33 publications in 1 language and 411 library holdings
Genres: History 
Roles: Author
Publication Timeline
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Most widely held works by Albert W Horst
A brief journey through the history of gun propulsion by Albert W Horst( )
1 edition published in 2005 in English and held by 130 WorldCat member libraries worldwide
Progress in modeling ignition in a solid propellant charge for telescoped ammunition by Michael J Nusca( )
1 edition published in 2005 in English and held by 128 WorldCat member libraries worldwide
Mortar interior ballistics sensitivity studies using IBHVG2 and progress toward a multidimensional representation by John R Schmidt( )
1 edition published in 2009 in English and held by 124 WorldCat member libraries worldwide
Experimental Validation for the Uniqueness of the Differential Pressure-Maximum Pressure Sensitivity Curve for Charge Safety Assessment ( Book )
1 edition published in 1982 in English and held by 1 WorldCat member library worldwide
One of the most used indicators of the level of longitudinal pressure waves in the gun environment is delta P sub i, the first negative minimum of the pressure difference curve measured between the breech and forward ends of the chamber. A current procedure for propelling charge safety assessment by the U.S. Army employs the correlation between delta P sub i and P sub max, the maximum chamber pressure, in order to project the expected probability of exceeding a given pressure limit. Major concerns exist both in terms of how to generate a P sub max vs. delta P sub i sensitivity curve and whether the curve is unique for a given charge/weapon interface. This study addresses one aspect of the problem, that of uniqueness, and hence the applicability of a curve generated by means of intentionally faulted igniter systems with respect to the broader and more ill-defined class of failures experienced over many firings in the field
A Brief Journey Through the History of Gun Propulsion ( )
1 edition published in 2005 in English and held by 1 WorldCat member library worldwide
While the use of guns and gun-like devices extends back in history for more than a millennium the past century has been marked by significant advances in the technology of guns the projectiles they launch and the propulsion systems employed to launch these projectiles to ever-increasing velocities. This report chronicles a sampling of theoretical and experimental advances in the science of gun propulsion and its application to a wide range of practical gun propulsion concepts
Mortar Interior Ballistics: Sensitivity Studies Using IBHVG2 and Progress Toward a Multidimensional Representation ( Book )
1 edition published in 2009 in English and held by 1 WorldCat member library worldwide
Traditionally, the interior ballistic (IB) modeling of mortars has been difficult to achieve because a mortar projectile contains certain energetic components internal to the tail boom. After ignition, high pressure generated by the igniter causes the canister to burst and release hot gases and burning particles into the larger chamber called the launch tube. Subsequently, any external charges ignite and produce gases which accelerate the projectile. A recent advancement to the IBHVG2 code allows the modeling of this high-low (HILO) configuration. This HILO feature comes with the introduction of two new parameters into the IBHVG2 model, essentially gas-phase and solid-phase discharge coefficients governing flow between the two chambers. The large-caliber gun community focuses on the impact of seven IB input variables (charge weight, force, propellant diameter, burning rate coefficient and exponent, covolume, and projectile weight) on the peak chamber pressure and projectile exit velocity. A sensitivity study on these input variables was performed on the high and low canister over a small range of the nominal value. The HILO feature was also examined for a 120-mm mortar. Uncertainty associated with the two new free parameters necessitated a wider range of investigation of said parameters
Multidimensional, Two-Phase Simulations of Notional Telescoped Ammunition Propelling Charge ( )
1 edition published in 2004 in English and held by 1 WorldCat member library worldwide
One of the many challenges facing weapon developers is the requirement for a highly lethal, lightweight, and compact large caliber gun system. One concept recently investigated by the U.S. Army is that of a swing-chamber gun, necessitating the use of telescoped ammunition. Such ammunition not only reduces the volume available for the propellant change, but also places severe geometric constraints on both the distribution of the propellant and the location and functionality of the ignition system. Lumped parameter codes cannot capture the influence of these configurational complexities on the processes of flame spreading and the formation of ensuing pressure waves. One-dimensional, two-phase flow interior ballistic simulations reveal the likelihood of such waves and raise the concern for possible damage to the ammunition (projectile). Multidimensional, two-phase interior ballistic simulations provide quantitative predictions of the flow in the annular region between the sidewall of the telescoped projectile and the cartridge case, also show the formation of pressure waves, and further the concern over projectile damage. Initial results are shown from ongoing work to couple an interior ballistics code with a gun/projectile structural dynamics code. Pressure waves in the charge produce a very demanding environment for the projectile which necessitates the use of a more substantial structure, with the attending sharp reduction in cargo capacity, or the use of exotic materials in order to insure a successful launch
A Study of Ammunition Response to the Interior Ballistics Environment of Gun Launch ( )
1 edition published in 2006 in English and held by 1 WorldCat member library worldwide
A multidisciplinary modeling approach is used to study the dynamic response of a notional telescoped ammunition projectile to gun chamber pressure dynamics generated by a densely packed solid propellant charge during gun launch. Since material stress imposed on the ammunition could potentially damage the projectile or its payload, a detailed knowledge of the peak stress is essential in the ammunition design process. The modeling approach begins with the Army's interior ballistics code ARL-NGEN3 predicting ignition, flamespreading and combustion of the solid propellant charge. Following this, the structural mechanics code EPIC simulates the response of the projectile to the pressure dynamics computed by the ARL-NGEN3 code. The results are analyzed in order to develop a comprehensive understanding of the in-bore behavior of the projectile
Experimental Studies of Ignition Phenomena in One-Dimensional Propelling Charges ( Book )
1 edition published in 1981 in English and held by 1 WorldCat member library worldwide
During the past decade, several unsteady, two-phase flow interior ballistic models have been developed which include treatment of ignition and flamespread through the propellant bed. While all such models were originally formulated under the simplifying assumption of one-dimensional flow, efforts are now underway to provide multi-dimensional representations, as well as to improve the descriptions of constitutive physical process. One important step, however, along the road to a phenomenologically complete model should be a critical assessment of available one-dimensional codes by means of comparison to 'one-dimensional' experiments. To that end, we describe herein a series of four, well-instrumented, 'one-dimensional, ' test firings conducted in the Navy 5-inch fiberglass breech gun. Two rounds were fired using Navy NOSOL 318 propellant, a solventless-processed gun propellant offering excellent control over grain dimensions and physical and chemical homogeneity. The other two rounds were fired with M30A1 triple-based gun propellant, employed in the Army 155-mm, M203, Propelling Charge. Data recorded during these tests included flame propagation, breech and sidewall gas pressure profiles, and sidewall case strains. Comparisons of experimental results with simple theoretical simulations of these events using the NOVA two-phase flow interior ballistics code are presented both to suggest possible areas of future concern to model developers and to assess the adequacy of current experimental techniques
A Simple Theoretical Analysis and Experimental Investigation of Burning Processes for Stick Propellant by Frederick W Robbins( Book )
1 edition published in 1983 in English and held by 1 WorldCat member library worldwide
The interior ballistic performance of propelling charges employing perforated unslotted stick propellant often cannot be simulated using either lumped-parameter or two-phase flow models without altering input data beyond realistic limits. In this work, a lumped-parameter model has been modified to account for enhanced burning within the perforations of stick propellant, a consequence of higher local pressures accompanying the choking of product gases exiting the perforations. A further extension allows treatment of additional surface area exposed should grain fracture occur as a result of excessive internal pressure. Results obtained using the modified code are compared to 155-mm howitzer firings. Data from closed-bomb firings which demonstrate the same effect are also included
Experimental Hypervelocity Firings Using Stick and Granular Propellant Configurations ( Book )
1 edition published in 1991 in English and held by 1 WorldCat member library worldwide
The suitability of lumped-parameter interior ballistic models for prediction of the interior ballistic performance of very high velocity guns is limited by use of a predetermined pressure gradient which is superimposed on the solution to approximate the relationship between space-mean, breech and projectile base pressures. Even modern two-phase flow interior ballistic models, specifically formulated to address the hydrodynamics of the problem, have not been extensively exercised in this regime. Only recently have limited, large- caliber gun firings with realistic projectile masses been conducted to provide required data in this velocity regime. In this study, firings were conducted in a long 120-mm gun at propellant charge to projectile mass ratios (C/M) of about 3 to 6, yielding muzzle velocities in the 2 - 2.7 km/s range. The tube was instrumented with pressure gages at various locations along its length to provide data for comparison to predictions of various interior ballistic codes
Continued Study of Stick Propellant Combustion Processes by Frederick W Robbins( Book )
1 edition published in 1983 in English and held by 1 WorldCat member library worldwide
The interior ballistic performance of propelling charges employing perforated, unslotted stick propellant often cannot be simulated using either lumped-parameter or two-phase-flow models, the experimental maximum pressure being much higher than calculated. A continuation of studies, initiated in FY81, into this anomalous performance has provided experimental evidence that the major contributor to this increase in pressure is splitting of the propellant sticks, a consequence of higher local pressures inside the long perforations of the unslotted sticks. Second-order effects include erosive burning or coning at the ends of the perforations and augmented burning rates on the progressive interior surfaces caused by the locally increased pressure. Other observations: slotted stick propellant was not found to split inside the gun, though fracturing occurred as the long grains tried to follow gas streamlines upon exiting a short-barreled test fixture; short, unslotted stick propellant, like slotted stick propellant, did not split during the interior ballistic event, yet produced greater muzzle velocities than predicted; and, finally, the NOVA two-phase-flow interior ballistic code provided good simulations of flamespread and pressurization inside the perforation of long, unslotted stick propellant
Detailed Characterization of Hypervelocity Firings in a Long 120-MM Gun ( Book )
1 edition published in 1991 in English and held by 1 WorldCat member library worldwide
The applicability of lumped-parameter interior ballistic models to very high velocity guns is limited by the use of a superimposed pressure gradient to approximate the relationship between the space mean, breech, and projectile base pressures. Even modern two-phase flow interior ballistic models, specifically formulated to address the hydrodynamics of the problem, are largely untested in such regimes. Serious attempts to develop high-velocity solid propellant guns, however, require an accurate modeling capability for concept screening and charge optimization. Firings were conducted in a long 120-mm gun (Ballistic Tube) at a propellant charge to projectile mass (C/M) ratio of about 3 to provide muzzle velocities in the 2 - 2.5 km/s range. The tube was instrumented with pressure gages at 14 locations to determine the experimental pressure-displacement profile. Results were compared to predictions of a classical lumped-parameter code, a state-of-the-art two-phase flow model, and a lumped-parameter code with a recently developed pressure gradient
New Directions in Multiphase Flow Interior Ballistic Modeling ( Book )
1 edition published in 1990 in English and held by 1 WorldCat member library worldwide
Over the past two decades, several two-phase-flow interior ballistic codes have been developed. Generally, they have treated ignition-induced pressure waves as a hydrodynamic problem which arises from the ignition stimulus, the propellant geometry, the path of flamespreading in the propellant bed, and the interaction of charge and chamber. Ignition and combustion have been treated as a simple process, with convectively-driven inert heating of the propellant until a surface-temperature criterion is reached, at which time an aP superscript n burning law describes the propellant surface regression, and all of the energy contained in the burned propellant is released immediately. The effects of propellant grain fracture, caused either by grain stress due to propellant bed compaction or by impact with fixed boundaries, has been outside the scope of the several codes. While the codes have incorporated interphase heat transfer and drag, they have been called inviscid, as the conservation laws are formulated to neglect the efforts of viscosity and heat conduction in the gas phase. This report describes, for the NOVA family of codes, (a) the recent inclusion of finite-rate chemistry and grain fracture, (b) planned efforts to improve the propellant near-field combustion model further, and (c) ongoing efforts to formulate a viscid/inviscid model to permit a linkage of effects with widely differing scales of heterogeneity. Keywords: Interior ballistics; Modeling; Kinetics; Viscosity. (jhd)
Ignition-Induced Flow Dynamics in Bagged-Charge Artillery ( )
1 edition published in 1980 in English and held by 1 WorldCat member library worldwide
Over recent years a number of efforts have been undertaken to develop interior ballistics models capable of treating ignition-induced, two-phase flow dynamics in gun chambers. A coincidental requirement was thus generated for experimental data usable for validation of such models. While data have been provided in the past on flame-front propagation as well as pressure- wave development in cased-ammunition guns, no direct information on flames spread in bagged charges was available. The initial confinement of the propellant bed and ignition species imposed by the bag, followed by allowable gas and solid phase mobilities in radial as well as axial directions upon bag rupture, could have a major impact on flamespread and flow dynamics during the early portion of the interior ballistic cycle. Such processes might significantly affect the usefulness of existing two-phase flow models formulated under an assumption of one-dimensional flow. Data are presented which reflect the recent results of efforts to characterize flame-front propagation, propellant-bed mobility and pressure-wave development in bagged charges. Some experimental results are compared to numerical simulations, and inferences are drawn both about the adequacy of the models and about the basic phenomenology of bagged-charge performance
High-Progressivity/Density (HPD) Propelling Charge Concepts; Progress of Programmed-Splitting Stick Propellant by Frederick W Robbins( Book )
1 edition published in 1986 in English and held by 1 WorldCat member library worldwide
This report summarizes progress to date on the manufacture and closed bomb evaluation of a new high-progressivity gun propellant configuration. The concept is known as programmed-splitting stick propellant and involves the use of embedded slits which are not initially exposed to hot ignition gases. Normal surface regression during burning, however, exposes the slits, typically after peak pressure has been reached in the gun, leading to a large increase in surface area and a corresponding increase in the mass generation rate. Accompanying increases in downbore pressures can lead to significant gains in muzzle velocity without any increase in maximum chamber pressure. At the time of this review, small lots of programmed-splitting stick propellant have been manufactured and subjected to closed bomb evaluation. The results of these tests indicate a high progressivity but not to the degree theoretically predicted. The disparity is postulated to be linked to a finite voidage associated with the slits in the actual grains and its possible influence on successful closure of the ends to ignition gases and mechanical behavior of the grains during the burning process
Charge Design Considerations and Their Effect on Pressure Waves in Guns ( Book )
1 edition published in 1980 in English and held by 1 WorldCat member library worldwide
Combustion instability, usually manifested as longitudinal pressure waves, has long been a serious problem in the design of high-performance, conventional guns. The source of this phenomenon was identified correctly to lie in the ignition phase of the interior ballistic cycle. Only recently, however, has it been understood that the ignition phase not only involves functioning of the igniter train components themselves but also depends on such factors as distribution of ullage, flow restrictions, and propellant bed mobility. The concepts of local as well as microscopic gas permeability have been shown to be important factors governing the formation, growth, and dissipation of pressure waves. High gas generation rates during the ignition and flamespreading phase, as defined by both burning surface and linear burning rates, also lead to increased levels of traveling pressure waves. The integration of these concepts into two-phase-flow interior ballistic codes now is beginning to allow a more precise unraveling of the interaction among these complex processes
The Charge Designer's Workbench: A Range of Interior Ballistic Modeling Tools ( )
1 edition published in 2006 in English and held by 1 WorldCat member library worldwide
Gun and ammunition designers typically employ various models initially to evaluate preliminary design concepts and ultimately to make specific decisions regarding the design and optimization of both individual components and all-up weapon systems. A wide range of computerized models exists today to address virtually every aspect of this process; in particular, the propelling charge designer has available several levels of interior ballistic models. These range from rather simple lumped-parameter models, providing basic performance data such as muzzle velocity and peak pressure and which run quickly on personal computers, to very complex multidimensional, multiphase flow models capable of describing the details of flamespreading, grain motion, and the formation of pressure waves, but employ specialized and occasionally unavailable input for propellant, charge, and gun parameters and require many hours on a workstation or supercomputer to complete the simulation. This report addresses the increasing level of physics and thus range of applicability to problems of increasing sophistication associated with three of today's most popular interior ballistic models: the lumped-parameter IBHVG2 code, the one-dimensional, two-phase flow XKTC code, and the state-of-the-art multidimensional, multiphase flow NGEN3 code. Recommendations are made with respect to the appropriate use of each of these highly useful tools, as well as the transferability of input data and comparability of results so obtained
A Comparison of Barrel-Heating Processes for Granular and Stick Propellant Charges ( Book )
1 edition published in 1982 in English and held by 1 WorldCat member library worldwide
The natural flow channels offered by propelling charges composed of bundles of stick propellant significantly reduce the resistance to gas flow when compared to that of granular propellant charges, virtually eliminating potentially damaging pressure waves in the gun chamber. However, this same feature which reduces pressure waves may also result in more propellant remaining in the chamber, burning behind the origin of rifling, and perhaps increasing barrel erosion. In this study, a two-phase flow interior ballistic code (NOVA) is employed to compare propellant motion and heat transfer processes for ballistically-equivalent stick and granular propellant charges. A large difference in the motion of the solid phase during ignition and combustion is predicted for the two configurations, leading ultimately to an approximately 300 K higher maximum wall temperature for the stick propellant charge
Continued Studies of Programmed-Splitting Stick Propellant by F. W Robbins( Book )
1 edition published in 1987 in English and held by 1 WorldCat member library worldwide
A number of high-progressivity, high-density (HPD) propelling charge concepts are being investigated to provide significant improvement in muzzle velocity with minimal system impact. The particular approach presented in this paper is based on a concept which allows the charge designer to program a substantial increase in the burning surface at any desired time in the interior ballistic cycle, typically after peak pressure has occurred and the pressure is falling rapidly as the projectile moves downbore. Thus, a very high loading density charge can be employed without excessive burning surface leading to overpressurization early in the cycle or insufficient burning surface leading to incomplete consumption of the charge upon projectile exit. This concept, applicable to a number of propellant configurations, has been exploited first as programmed-splitting stick (PSS) propellant. Progress at the time of this writing is reported, including performance predictions, manufacturing experience, gun firings, and modeling efforts. Keywords: Gun propellant, High progressivity, High velocity, Guns, Efficiency, Stick propellant, Interior ballistics
 
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