Comments on the effect of punched and lain fuze covers on the aerodynamic properties of the 90-MM T91E1 shell at M=1.2 /

The effect of two different fuze covers, punched and plain, of the M51A5 fuze on the aerodynamics of the 90-mm T91E1 shell are discussed. The nonlinearities of the aerodynamic properties at a Mach number of 1.2 are also given. (Author)."Department of the Army Project No. 5B03-03-001; Ordnance Research and Development Project No. TB3-0108.""May 1957."Includes bibliographic references (page 8).The effect of two different fuze covers, punched and plain, of the M51A5 fuze on the aerodynamics of the 90-mm T91E1 shell are discussed. The nonlinearities of the aerodynamic properties at a Mach number of 1.2 are also given. (Author).Mode of access: Internet

Correction of non-linearity in electromagnetic weighing devices /

"Department of the Army Project No. 5B0306004; Ordnance Research and Development Project No. TB3-0108.""February 1956."Mode of access: Internet

Free oscillations of liquid during spin-up /

Eigenfrequencies of a liquid in a fully-filled circular cylinder during spin-up are shown to be always real (hence the flow is stable), provided that there is no singularity (critical layer) in the flow. For rotationally symmetric disturbances the liquid eigenfrequencies at several successive instants during the phase of spin-up are determined. The conditions for the existence, the location, as well as the nature of the singularity based on an inviscid formulation are demonstrated. Regular and singular solutions of the inviscid system having a critical layer in the flow, are obtained in series form. The exact viscous system governing amplitudes of arbitrary disturbances is reduced to two coupled equations in two dependent variables. A differential equation governing approximately the viscous disturbances in the vicinity of a singularity is obtained. (Author)."August 1973."Includes bibliographic references (page 43).Eigenfrequencies of a liquid in a fully-filled circular cylinder during spin-up are shown to be always real (hence the flow is stable), provided that there is no singularity (critical layer) in the flow. For rotationally symmetric disturbances the liquid eigenfrequencies at several successive instants during the phase of spin-up are determined. The conditions for the existence, the location, as well as the nature of the singularity based on an inviscid formulation are demonstrated. Regular and singular solutions of the inviscid system having a critical layer in the flow, are obtained in series form. The exact viscous system governing amplitudes of arbitrary disturbances is reduced to two coupled equations in two dependent variables. A differential equation governing approximately the viscous disturbances in the vicinity of a singularity is obtained. (Author).RDT & E Project no. ;Mode of access: Internet

Estimation of the static aerodynamic characteristics of ordnance projectiles at supersonic speeds /

A simplified flow field solution has been programmed in an attempt to improve the accuracy of estimates of the static aerodynamic characteristics of ordnance projectiles. It provides estimates of drag, normal force, static moment, and roll damping moment for pointed bodies of revolution at supersonic speed. The program combines the Van Dyke hybrid theory for potential flow, the Van Driest compressible turbulent boundary layer theory, and the Chapman-Sternberg model for supersonic base pressure. Good agreement is demonstrated between the theoretical and experimental data."November 1973."Includes bibliographic references (pages 53-55).A simplified flow field solution has been programmed in an attempt to improve the accuracy of estimates of the static aerodynamic characteristics of ordnance projectiles. It provides estimates of drag, normal force, static moment, and roll damping moment for pointed bodies of revolution at supersonic speed. The program combines the Van Dyke hybrid theory for potential flow, the Van Driest compressible turbulent boundary layer theory, and the Chapman-Sternberg model for supersonic base pressure. Good agreement is demonstrated between the theoretical and experimental data.RDT & E Project no. ;Mode of access: Internet

The effect of muzzle jet asymmetry on projectile motion /

Gas dynamic loadings experienced by a projectile passing through the muzzle gas flow field are investigated by inducing deliberate asymmetries in the muzzle flow. The effect of these asymmetries on projectile yawing motion near first maximum yaw is measured in a ballistics range. The measured data is extrapolated back to the muzzle, and the projectile angular velocity upon penetration of the muzzle blast is evaluated. The projectile linear velocity imparted by the asymmetric gas dynamic loadings is estimated using the hypersonic equivalence principle. The total jump of the projectile trajectory due to both angular and linear velocity is computed and compared with measured values. (Author)."January 1975."Includes bibliographical references (pages 39-40).Gas dynamic loadings experienced by a projectile passing through the muzzle gas flow field are investigated by inducing deliberate asymmetries in the muzzle flow. The effect of these asymmetries on projectile yawing motion near first maximum yaw is measured in a ballistics range. The measured data is extrapolated back to the muzzle, and the projectile angular velocity upon penetration of the muzzle blast is evaluated. The projectile linear velocity imparted by the asymmetric gas dynamic loadings is estimated using the hypersonic equivalence principle. The total jump of the projectile trajectory due to both angular and linear velocity is computed and compared with measured values. (Author).RDT & E Project no. ;Mode of access: Internet

Evaluation of the computer codes BLAST, DORF, HELP and HEMP for suitability of underexpanded jet flow calculation /

The computer codes BLAST, DORF, HELP and HEMP have been used to simulate the flow field at the muzzle of a M-16 rifle, without any deflectors, compensators, or flash hiders. The flow was modeled as an underexpanded jet, of a compressible, inviscid and non-reactive gas. The calculations, restricted to the initial stages of formation of the jet were done on a cylindrically symmetric geometry without the presence of a flow obstruction in the form of a projectile. Results are presented as pressure contours as well as pressure and velocity profiles at different angles from the centerline of the muzzle of the barrel, and plots of pressure versus distance from the muzzle. The calculations are compared with available photographic records of the process. (Author)."August 1973."Includes bibliographic references (pages 61-62).The computer codes BLAST, DORF, HELP and HEMP have been used to simulate the flow field at the muzzle of a M-16 rifle, without any deflectors, compensators, or flash hiders. The flow was modeled as an underexpanded jet, of a compressible, inviscid and non-reactive gas. The calculations, restricted to the initial stages of formation of the jet were done on a cylindrically symmetric geometry without the presence of a flow obstruction in the form of a projectile. Results are presented as pressure contours as well as pressure and velocity profiles at different angles from the centerline of the muzzle of the barrel, and plots of pressure versus distance from the muzzle. The calculations are compared with available photographic records of the process. (Author).RDT & E Project no. ;Mode of access: Internet

On-board projectile measurements for exterior ballistics /

"This report was presented as a paper at The Ballistic Environmental Measurements Symposium for Tube-Fired Munitions held at Aberdeen Proving Ground, May-24-25, 1972.""September 1972."Includes bibliographic references (pages 44-55).RDT & E Project no. ;Mode of access: Internet

Cooling water system, compressor plant no. 1 /

In the operation of the BRL Supersonic Wind Tunnels it is necessary to hold the air temperature at the entrance to the tunnels to a constant given level. This report describes the cooling system used to accomplish this and a few of the problems involved in its operation. (Author).See errata issued 18 July 1968 for pages 9, 17, 20, 61 and 68 at end of item."June 1970."In the operation of the BRL Supersonic Wind Tunnels it is necessary to hold the air temperature at the entrance to the tunnels to a constant given level. This report describes the cooling system used to accomplish this and a few of the problems involved in its operation. (Author).RDT &E Project No. :Mode of access: Internet

Numerical experiments to integrate the Navier-Stokes equations /

A series of numerical experiments are described which solve for the time dependent flow field around a circular cylinder accelerated to supersonic speeds. The study is performed using a computer program developed by Scala and Gordon which models the full time-dependent Navier-Stokes equations. Results are presented for Mach two flow past a cylinder at freestream Reynolds numbers of 15.0, 46.8, 157.2, and 704.6, based on cylinder diameter. The numerical results are compared with analytical solutions and experimental measurements and the accuracy of the numerical results is discussed. These comparisons show where the author's numerical solutions of the Navier-Stokes equations fail to give accurate results."April 1972."Includes bibliographic references (pages 48-49).A series of numerical experiments are described which solve for the time dependent flow field around a circular cylinder accelerated to supersonic speeds. The study is performed using a computer program developed by Scala and Gordon which models the full time-dependent Navier-Stokes equations. Results are presented for Mach two flow past a cylinder at freestream Reynolds numbers of 15.0, 46.8, 157.2, and 704.6, based on cylinder diameter. The numerical results are compared with analytical solutions and experimental measurements and the accuracy of the numerical results is discussed. These comparisons show where the author's numerical solutions of the Navier-Stokes equations fail to give accurate results.RDT & E Project no. ;Mode of access: Internet

Measurement of electron concentrations in an axisymmetric nonequilibrium shock layer /

The report describes an experiment to map the electron number density distribution in a nonequilibrium shock layer in which kinetic and radiative processes are coupled to gasdynamics. The experimental method is two-wavelength interferometry using a Mach-Zehnder optical interferometer backlighted by a giant pulse ruby laser. On the stagnation streamline agreement was observed between the maximum measured electron number density and the value computed for ionization equilibrium, accounting for experimental error and the lowering of ionization potential. (Author)."June 1972."Includes bibliographic references (pages 44-46).The report describes an experiment to map the electron number density distribution in a nonequilibrium shock layer in which kinetic and radiative processes are coupled to gasdynamics. The experimental method is two-wavelength interferometry using a Mach-Zehnder optical interferometer backlighted by a giant pulse ruby laser. On the stagnation streamline agreement was observed between the maximum measured electron number density and the value computed for ionization equilibrium, accounting for experimental error and the lowering of ionization potential. (Author).RDT & E Project no. ;Mode of access: Internet