Shock Wave Development Within Expansive Flows

2018 ◽  
pp. 221-230
Author(s):  
Beric W. Skews ◽  
Randall T. Paton
Keyword(s):  
Shock Wave ◽  
Wave Development ◽  
Expansive Flows

scholarly journals A study of the interaction of a travelling shock wave with a solid-propellant rocket motor head end

2021 ◽  
Author(s):  
Robert Elian Feteanu
Keyword(s):  
Shock Wave ◽  
Rocket Motor ◽  
Combustion Chambers ◽  
Cfd Simulations ◽  
Radial Wave ◽  
Flow Models ◽  
Numerical Studies ◽  
Solid Propellant Rocket ◽  
Wave Development ◽  
Solid Rocket

Experimental and numerical studies have been undertaken to examine various aspects pertaining to the interaction of an incident travelling shock wave with a solid rocket motor's head end (forward section), in order to identify any potential gasdynamic mechanism of wave reinforcement pertinent to combustion instability behaviour in these motors. A cold-flow experiment, based on a shock tube scheme tailored to the present application, has proved to be useful in providing information surrounding the interaction process. Both experimental and numerical results (CFD simulations) confirm the existence of substantial transient radial wave development superimposed on the base reflected axial shock wave. These results illustrate the potential weakness of one-dimensional flow models for certain engineering applications, where important multidimensional phenomena, such as those observed in this work, may not be captured. By analogy to actual propulsion system combustion chambers, the transverse wave activity is potentially a factor in supporting an augmentation of the local combustion rate in the head-end region of a rocket motor combustor.

The Integrated Gas/Steam Nozzle With Steam Cooling: Part II — Design Considerations

1984 ◽  
Author(s):  
Ivan G. Rice
Keyword(s):  
Shock Wave ◽  
Film Cooling ◽  
Fat Body ◽  
Suction Side ◽  
Body Type ◽  
Trailing Edge ◽  
Cooling Effectiveness ◽  
Film Cooling Effectiveness ◽  
Wave Development ◽  
Gas Nozzle

The integration of multiple steam nozzles with the first-stage annular-gas nozzle to form a binary-flow system in a reheat-gas turbine is presented whereby steam is first used as an internal vane coolant before being expanded and accelerated for work extraction. Steam nozzles are located in “fat-body” type vanes. Trailing-edge impingement followed by reverse-serpentine-flow cooling takes place. Internal trailing-edge-steam nozzles produce either diffusion or shock-wave boundary-layer disturbance inside the trailing edge to enhance heat transfer. Externally, steam blanketing reduces nozzle-profile loss and improves film cooling effectiveness by reducing the surface viscosity and secondly by controlling suction-side aft-shock-wave development. A new vane shape coupled with a gas-turning-combustor system is suggested to improve vane-film cooling effectiveness further.

Shock wave development in couple stress fluid-filled thin elastic tubes

2015 ◽  
Vol 130 (6) ◽  
Author(s):  
Samuel O. Adesanya ◽  
Mostafa Eslami ◽  
Mohammad Mirzazadeh ◽  
Anjan Biswas
Keyword(s):  
Shock Wave ◽  
Couple Stress ◽  
Couple Stress Fluid ◽  
Elastic Tubes ◽  
Wave Development

Shock Wave Development and Propagation in Automobile Exhaust Systems

1988 ◽  
Author(s):  
Noriaki Sekine ◽  
Shuji Matsumura ◽  
Kazuyoshi Takayama ◽  
Osamu Onodera ◽  
Katsuhiro Ito
Keyword(s):  
Shock Wave ◽  
Automobile Exhaust ◽  
Wave Development ◽  
Exhaust Systems

scholarly journals Effect of wavy wall strut fuel injector on shock wave development and mixing enhancement of fuel and air for a scramjet combustor

2020 ◽  
Author(s):  
Obula Reddy Kummitha ◽  
K M Pandey
Keyword(s):  
Shock Wave ◽  
Mach Number ◽  
Shock Waves ◽  
Shear Layer ◽  
Wave Generation ◽  
Wavy Wall ◽  
Fuel Injector ◽  
Shock Wave Generation ◽  
Shear Mixing ◽  
Wave Development

Abstract The shear mixing and streamline vortices are the notable parameters to influence the air–fuel mixing in hypersonic flows. The shock wave development and Mach number significantly influence the shear mixing phenomenon. Hence, this research introduced an unconventional strut and tested its performance for the generation of shock waves at different flow conditions (M = 2,4,6). The Reynolds-averaged Navier–Stokes equations are solved to evaluate the performance of the new strut. Both the DLR scramjet strut injector and wavy wall strut injector are assessed for the shear mixing development. Turbulence for the association of shock waves, mixing layer, and the boundary layer has been modeled with the SST k-ω model. The variation in shock development and its interactions are investigated further with an increase in Mach number. The scramjet flow structure differentiation found the increased number of oblique shock waves with the wavy wall strut fuel injector. It increases the turbulence level with increased streamline vortices, turbulent intensity, and turbulent kinetic energy. The shock wave generation analysis at different Mach numbers (M = 2,4,6) found fewer interactions between the shock wave and shear layer with increased Mach number. From the examination of shock wave generation and its interaction with the shear layer and analysis of turbulent parameters, it is found that the wavy wall strut has an appreciable effect on shock-induced blend augmentation of fuel and air.

scholarly journals Unsteady shock wave dynamics in accelerating and decelerating flight

2021 ◽  
pp. 1-23
Author(s):  
I. Mahomed ◽  
H. Roohani ◽  
B.W. Skews ◽  
I.M.A. Gledhill
Keyword(s):  
Shock Wave ◽  
Steady State ◽  
Mach Number ◽  
Cone Angle ◽  
Shock Interactions ◽  
Acceleration Technique ◽  
Axial Acceleration ◽  
Wave Development ◽  
History Effect ◽  
Commercial Solver

Abstract Increasingly agile manoeuvre is an advantage in the flight of aircraft, missiles and aerial vehicles, but the principles of accelerating aerodynamics in the transonic regime are only now being fully investigated. This study contributes to the understanding of shock and separation effects on drag during axial acceleration, using a simple geometric configuration. Unsteady shock wave behavior was numerically investigated for an axisymmetric cone-cylinder using a commercial solver and the Moving Reference Frame acceleration technique. This acceleration technique was validated using unsteady numerical and experimental methods. The cone-cylinder was accelerated from Mach number 0.6 to Mach number 1.2 at 100g constant and deceleration was from Mach number 1.2 until Mach number 0.6 at –100g constant. Three cone angles were tested for the cone-cylinder with uniform cylinder diameter. Acceleration through the transonic Mach regime was characterised by a delayed and gradual shock wave development when compared to steady state, demonstrating a clear flow history effect. Deceleration through the transonic Mach regime was characterised by shock wave propagation from the base to the nose. New flow structures appeared during deceleration that do not have counterparts in the steady state, including shock interactions and propagating expansion-compression features. Gross changes in the unsteady drag coefficient curves for each cone-angle are explained with reference to unsteady shock wave behaviour for accelerating and decelerating motion.

scholarly journals A study of the interaction of a travelling shock wave with a solid-propellant rocket motor head end

2021 ◽  
Author(s):  
Robert Elian Feteanu
Keyword(s):  
Shock Wave ◽  
Rocket Motor ◽  
Combustion Chambers ◽  
Cfd Simulations ◽  
Radial Wave ◽  
Flow Models ◽  
Numerical Studies ◽  
Solid Propellant Rocket ◽  
Wave Development ◽  
Solid Rocket

Experimental and numerical studies have been undertaken to examine various aspects pertaining to the interaction of an incident travelling shock wave with a solid rocket motor's head end (forward section), in order to identify any potential gasdynamic mechanism of wave reinforcement pertinent to combustion instability behaviour in these motors. A cold-flow experiment, based on a shock tube scheme tailored to the present application, has proved to be useful in providing information surrounding the interaction process. Both experimental and numerical results (CFD simulations) confirm the existence of substantial transient radial wave development superimposed on the base reflected axial shock wave. These results illustrate the potential weakness of one-dimensional flow models for certain engineering applications, where important multidimensional phenomena, such as those observed in this work, may not be captured. By analogy to actual propulsion system combustion chambers, the transverse wave activity is potentially a factor in supporting an augmentation of the local combustion rate in the head-end region of a rocket motor combustor.

The Integrated Gas/Steam Nozzle With Steam Cooling: Part I — Application

1984 ◽  
Author(s):  
Ivan G. Rice
Keyword(s):  
Shock Wave ◽  
Film Cooling ◽  
Fat Body ◽  
Suction Side ◽  
Body Type ◽  
Trailing Edge ◽  
Cooling Effectiveness ◽  
Film Cooling Effectiveness ◽  
Wave Development ◽  
Gas Nozzle

The integration of multiple steam nozzles with the first-stage annular-gas nozzle to form a binary-flow system in a reheat-gas turbine is presented whereby steam is first used as an internal vane coolant before being expanded and accelerated for work extraction. Steam nozzles are located in “fat-body” type vanes. Trailing-edge impingement followed by reverse-serpentine-flow cooling takes place. Internal trailing-edge-steam nozzles produce either diffusion or shock-wave boundary-layer disturbance inside the trailing edge to enhance heat transfer. Externally, steam blanketing reduces nozzle-profile loss and improves film cooling effectiveness by reducing the surface viscosity and secondly by controlling suction-side aft-shock-wave development. A new vane shape coupled with a gas-turning-combustor system is suggested to improve vane-film-cooling effectiveness further.

On the evolution of compression pulses in an exploding atmosphere: initial behaviour

1979 ◽  
Vol 94 (1) ◽  
pp. 195-208 ◽  
Author(s):  
J. F. Clarke
Keyword(s):  
Shock Wave ◽  
Present Theory ◽  
Sine Wave ◽  
Inert Atmosphere ◽  
Subsequent Evolution ◽  
Local Explosion ◽  
Wave Development ◽  
Amplifying Effect ◽  
Shock Fitting ◽  
Positive Half

The development in space and time of a plane initial disturbance to a spatially uniform exploding atmosphere is analysed on the assumption that the disturbance amplitude is comparable in magnitude with the inverse (dimensionless) activation energy of the explosion reaction. Particular attention is focused on the shock-fitting problem, which has features that distinguish it from its inert-atmosphere counterpart.Using the positive half of a sine wave to typify an isolated compression perturbation, it is found that the amplifying effect of the ambient reaction leads to very rapid shock wave development, which depends significantly on the spatial extent of the disturbance. The latter also influences the question of whether local explosion (local explosion is recognized here as a logarithmically unbounded growth of the disturbance amplitude; in other words as a local breakdown of the present approximations) occurs at the shock wave or some distance behind it. The subsequent evolution of these two states will no doubt be significantly different, but the answer to this speculation must await extension of the present theory to encompass the rapid events that ensue near the local explosion regions.

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