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Investigation of the Attenuation of Plane Shock Waves Moving over very Rough Surfaces

Description: Experimental measurements of the attenuation of plane shock waves moving over rough walls have been made in a shock tube. Measurements of the boundary-layer characteristics, including thickness and velocity distribution behind the shock, have also been made with the aid of new cal techniques which provide direct information on the local boundary-layer conditions at the rough walls. Measurements of shock speed and shock pressure ratio are presented for both smooth-wall and rough-wall flow over lengths of machined-smooth and rough strips which lined all four walls of the shock tube. A simplified theory based on Von Karman's expression for skin-friction coefficient for flow over rough walls, along with a wave-model concept and extensions to include time effects, is presented. In this theory, the shock-tube flow is assumed to be one-dimensional at all times and the wave-model concept is used to relate the local layer growth to decreases in shock strength. This concept assumes that local boundary-layer growths act as local mass-flow sinks, which give rise to expansion waves which, in turn, overtake the shock and lower its mass flow accordingly.
Date: June 16, 1953
Creator: Huber, Paul W.; McFarland, Donald R. & Levine, Philip
Partner: UNT Libraries Government Documents Department

Visual observations of the shock wave in flight

Description: From Summary: "This report presents the results of pilot observations and photographs of the compression shock wave on the wing of an airplane in flight. A detailed description of the test conditions necessary and the procedure to be following in producing the visible shock are presented. The pilot's observations of the occurrence of an oscillating shock wave and its possible relationship with the airplane buffeting are also presented."
Date: May 24, 1948
Creator: Cooper, George E. & Rathert, George A., Jr.
Partner: UNT Libraries Government Documents Department

Boundary Disturbances in High Explosive Shock Tubes

Description: From abstract: High velocity disturbances are observed to propagate along the walls of a high explosive operated shock tube in advance of the plane shock. Experiments are presented which determine the dependence of the geometry, energy, and velocity of the disturbance on such variables as the gas contained in the shock tube, the shock strength, and the roughness and composition of the supporting boundary. A model is constructed to explain the flow within the disturbance. Arguments are presented which show the disturbance to result from radiation originating in the luminous plane shock...The purpose of this paper is to present the results of initial investigations made in an effort to describe the phenomenon of strong shocks developed in a shock tube by the detonation of high explosive charge.
Date: May 26, 1952
Creator: Shreffler, R. G. & Christian, R. H.
Partner: UNT Libraries Government Documents Department

Boundary Disturbances in High Explosive Shock Tubes

Description: Abstract: High Velocity disturbance are observed to propagate in advance of the plane shock front along the walls of a high-explosive-operated shock tube. Experiments were performed which indicate that the disturbance proceeds at a constant velocity relative to the shock front, and carries a considerable amount of energy as evidenced by its ability to penetrate metal plates. The velocity of a similar disturbance observed along a rod placed on the axis of the shock tube normal to the plane shock front was essentially independent of the rod material and diameter. This phenomenon was observed when shock tubes were filled with argon or chlorine but was absent when air or helium was used.
Date: March 31, 1952
Creator: Shreffler, R. G.
Partner: UNT Libraries Government Documents Department

A study of the transient behavior of shock waves in transonic channels flows

Description: Report presenting an investigation of the accuracy of the result obtained in a fundamental paper by Kantrowitz that a small short-time lowering of the back pressure in steady, shock-free, transonic diffuser flow causes a stationary or trapped shock to form near the critical shock channel throat.
Date: October 1952
Creator: Hess, Robert V.
Partner: UNT Libraries Government Documents Department

A flight investigation of laminar and turbulent boundary layers passing through shock waves at full-scale Reynolds numbers

Description: Report presenting an investigation in flight at free-stream Mach numbers up to 0.76 to determine the behavior of laminar and turbulent boundary layers passing through shock waves. Boundary-layer and pressure-distribution measurements were made on a short-span airfoil built around a wing of a fighter airplane. Results regarding laminar flow ahead of the shock wave, turbulent flow ahead of the shock wave, comparison at full scale of laminar and turbulent boundary layers, and effect of Reynolds numbers on boundary-layer profiles with shock waves are provided.
Date: December 1953
Creator: Harrin, Eziaslav N.
Partner: UNT Libraries Government Documents Department

Calculations of the rate of thermal dissociation of air behind normal shock waves at Mach numbers of 10, 12, and 14

Description: Report presenting the rate equation for the dissociation of air, based on simple-collision theory, and the numerical values of the factors that enter it. The rate equation and conservation equations for a flowing dissociating gas are solved for the conditions behind normal shock waves at Mach numbers of 10, 12, and 14. Results regarding the adjustment of translation, rotation, and vibration and adjustment of dissociation are provided.
Date: April 1956
Creator: Wood, George P.
Partner: UNT Libraries Government Documents Department

Study of the pressure rise across shock waves required to separate laminar and turbulent boundary layers

Description: Results are presented of a dimensional study and an experimental investigation of the pressure rise across a shock wave which causes separation of the boundary layer on a flat plate. The experimental part of the investigation was conducted at a Mach number of 3.03 for a Reynolds number range of 2 x 10 (sup) 6 to 19 x 10 (sup) 6. The available experimental data are compared with the predictions of the present study, and the significance of the results obtained is discussed relative to certain practical design problems.
Date: September 1952
Creator: Donaldson, Coleman duP. & Lange, Roy H.
Partner: UNT Libraries Government Documents Department

Study of the pressure rise across shock waves required to separate laminar and turbulent boundary layers

Description: Report presenting a study and experimental investigation on the pressure rise across shock waves required to cause separation of the boundary layer on a flat plate. The interaction of shock wave and boundary layer was investigated experimentally when the boundary layer was caused to separate from the surface of a tube. Results regarding testing and correlation with other results are provided.
Date: May 5, 1952
Creator: Donaldson, Coleman DuP. & Lange, Roy H.
Partner: UNT Libraries Government Documents Department

Shock-turbulence interaction and the generation of noise

Description: Interaction of convected field of turbulence with shock wave is analyzed to yield modified turbulence, entropy spottiness, and noise generated downstream of the shock. Analysis is generalization of single-spectrum-wave treatment of NACA-TN-2864. Formulas for spectra and correlations are obtained. Numerical calculations yield curves of rms velocity components, temperature, pressure, and noise in db against Mach number for m = 1 to infinity; both isotropic and strongly axisymmetric (lateral/longitudinal = 36/1) initial turbulence are treated. In either case, turbulence of 0.1 percent longitudinal component generates about 120 dbs of noise.
Date: June 3, 1954
Creator: Ribner, H. S.
Partner: UNT Libraries Government Documents Department

Shock-turbulence interaction and the generation of noise

Description: Report presenting the interaction of a convected field of turbulence with a shock wave, which has been analyzed to yield the modified turbulence, entropy spottiness, and noise generated downstream of the shock. The results in this report are applicable quantitatively to flow in ducts or channels containing normal shocks.
Date: July 1954
Creator: Ribner, H. S.
Partner: UNT Libraries Government Documents Department

An Experimental Method to Determine Equation of State Data for Solids by Shock Wave Measurements

Description: The following report describes and experimental method used to determine equation of state of materials under strong shock. The method was devised of simultaneously measuring the velocity of the shock through a plate, and the velocity of the free surface after the shock has traversed the plate. Further analysis is presented.
Date: 1953
Creator: Christian, Russell H. & Walsh, John M.
Partner: UNT Libraries Government Documents Department

Earthquakes in California in 1893

Description: A report about recorded shock waves observed or felt on Mount Hamilton, and all those reported to the Lick Observatory by letter, as well as newspaper reports of such earthquakes that occurred in California during that year.
Date: 1894
Creator: Perrine, Charles D.
Partner: UNT Libraries Government Documents Department

A SIMPLIFIED DESCRIPTION OF SPHERICAL AND CYLINDRICAL BLAST WAVES

Description: A theory is developed by which the motion of the main shock wave originating from cylindrical and spherical blats, as well as the formation and subsequent motion of the secondary shock. are given by explicit formulas. A formulation for giving the location of the contact surface between the detonation gases and the outside atmosphere was obtained. (auth)
Date: August 1, 1960
Creator: Friedman, M.P.
Partner: UNT Libraries Government Documents Department

Shock transmission and reflection from a material interface and subsequent reflection from a hard boundary

Description: As a shock wave passes through a material interface into a region of higher density (the receiver material), a trans- mitted and reflected shock wave are both generated and the interface is set into motion. The speeds of the transmitted shock, reflected shock, and interface are related to the ini- tial shock speed and material properties via a set of coupled nonlinear equations that, in general, cannot be easily solved analytically. In this report, we derive the equations which describe this process and we document a numerical routine which solves the nonlinear equations. We then go on to solve the problem of finding the position where the interface col- lides with the transmitted shock wave once the transmitted shock wave is reflected from an impenetrable boundary lo- cated somewhere away from the initial material interface. Fi- nally, we compare the analytical predictions with the CALE simulation running in 1-D.
Date: November 20, 1998
Creator: Hurricane, O A & Miller, P L
Partner: UNT Libraries Government Documents Department

Analysis of shock motion in ducts during disturbances in downstream pressure

Description: From Summary: "The effect of small downstream pressure distributions on the position of a normal shock in a duct with area variation is analyzed. For the analysis, the gas flow is treated as quasi-one-dimensional, and boundary layer is neglected. The analysis shows that there is a first-order lag relation between shock position and small downstream disturbances in pressure which occur at frequencies below a given limit."
Date: September 1957
Creator: Hurrell, Herbert G.
Partner: UNT Libraries Government Documents Department

Gaseous Detonation : Bibliography

Description: This report is a bibliography divided into two sections: one that documents books and journal articles, the other containing classified and unclassified documents, that are based around gaseous detonation. These sources cover the period between 1941 to October of 1957.
Date: October 28, 1957
Creator: Maynard, G. R. & Frost, Fred
Partner: UNT Libraries Government Documents Department

Close-in Air Blast from a Row Charge in Basalt

Description: From abstract: Close-in air blast measurements were made on the Dugout shot. Major constituents of the blast wave were the ground-shock-induced pulse and the pulse from venting gases. The ground-shock-induced pulse was the dominant one at all stations.
Date: August 4, 1965
Creator: Vortman, Luke J.
Partner: UNT Libraries Government Documents Department