Control of the Shape and Position of a Bow Shock Wave, Drag and Lift Forces, and Self-Sustained Flow Pulsations Using Stratified Energy Supply |Chapter 8 | Physical Science: New Insights and Developments Vol. 3

 

In this study, a method for controlling high-speed flows using a continuously acting thermally stratified energy deposition is presented. The study analyses the dependence of the shape and position of a bow shock wave, drag and lift forces, and self-sustained flow pulsations on the temperature values ​​in the layers of a stratified energy source acting on an aerodynamic body. Numerical modelling is based on the system of the Navier-Stokes equations for viscous heat-conducting gas (air) at freestream Mach number M∞=2. A detailed visualisation of the dynamics of the density, pressure, temperature, and local Mach number fields during the controlled establishment of steady-state flow regimes is presented. Multiple manifestation of the Richtmyer–Meshkov instability is demonstrated. Sharp peaks accompanying the development of Richtmyer–Meshkov instabilities are observed. These peaks persist even in the steady-state flow regime established under the action of stratified energy supply, changing the shape of the bow shock wave and giving it a wavy form. Basic approaches to controlling the shape and position of the bow shock wave, drag, and lift (pitch) forces (at zero angle of attack), as well as stability in steady-state supersonic flow past an aerodynamic body, have been developed using a continuously operating thermally stratified energy deposition. The possibility of generating and damping self-sustaining flow pulsations, as well as the formation of a steady flow with opposing, continuously acting lift forces, is demonstrated by changing the temperature in the layers of the thermally stratified energy source. The practical application of the developed methods for control of the characteristics and stability of high-speed flow/flight can be associated with the development of non-mechanical control systems for aircraft at the stage of echelon (horizontal) flight.

 

Author(s) Details

 

O. A. Azarova
Federal Research Center “Computer Science and Control” of the Russian Academy of Sciences, Vavilova Str. 44, Moscow 119333, Russia.

 

Please see the book here :- https://doi.org/10.9734/bpi/psniad/v3/6675

 

Triple-Shock Configurations in High-Speed Flows Over Plane and Cylinder Bodies in Different Gases | Chapter 8 | Physical Science: New Insights and Developments Vol. 2

 

Flow control is crucial for refining the quality of high-speed flows and improving the performance and safety of fast aircraft. Unsteady flow control through external energy deposition has been widely discussed in the literature. Such processes often involve complex shock wave interactions, including the occurrence of triple shock configurations. This сhapter considers the issues of controlling supersonic flow past aerodynamic bodies under the action of external energy supply. The mechanism of interaction of the bow shock wave with an oblique shock wave formed by the refraction of the bow shock wave on the outer surface of the energy source is revealed. Unsteady triple-shock configurations near the surface of compound cylindrical bodies "hemisphere-cylinder" and "hemisphere-cone-cylinder" under the action of external energy supply for gaseous media with an adiabatic index of 1.4 and 1.2 are investigated at freestream Mach number M = 4. The studies are carried out numerically based on the Euler equations. Complex-conservative difference schemes are used in the simulations. The influence of the triple-shock configuration on the surface pressure is investigated and the formation of local spatio-temporal regions of the increased pressure is established. It is shown that the mechanism of pressure growth at the boundary, together with the local increase in the drag force, is associated with the action of the vortex flow, as well as with the action of the resulting shock wave structures. The dependences of the angles of the three-shock configuration on the rarefaction coefficient in the energy input region and on the angle of the incident shock wave are obtained. A comparison with the plane case is made. Obtained results can be used for organization of flow control with the use of external energy deposition by means of laser, microwave or electrical discharge.

 

 

Author(s) Details

OLGA AZAROVA
Department of Mathematical Modeling of Computer-Aided Design Systems, Federal Research Center “Computer Science and Control” of RAS, Vavilova St. 40, 119333, Moscow, Russia.

 

LUDMILA GVOZDEVA
Department of Physical Gas Dynamics, Joint Institute for High Temperatures RAS, Izhorskaya Str. 13/2, 125412, Moscow, Russia.

 

OLEG KRAVCHENKO
Department of Mathematical Modeling of Computer-Aided Design Systems, Federal Research Center“Computer Science and Control” of RAS, Vavilova St. 40, 119333, Moscow, Russia.

 

Please see the book here :- https://doi.org/10.9734/bpi/psniad/v2/6358

Cooling of an Exhaust Chamber of Jet Engine by Near-Wall Swirl Gas and Liquid Flow | Chapter 7 | Physical Science: New Insights and Developments Vol. 1

This paper addressed the problems of supersonic flow turning at the Laval nozzle outlet and the protection of the confining surface against combustion products. In both cases, the swirl of the near-wall jet plays an active role. In the context of vortex motion, radial pressure gradient emerges, thereby serving as a mechanism for controlling supersonic flow and changing its direction. Furthermore, the swirl near-wall jet can be used independently or in combination with a cooling liquid film for surface protection. As an example, supersonic flow in a conical Laval nozzle with an exhaust into a channel with a small constriction is considered. A swirl near-wall jet is organised at the nozzle outlet. The liquid is either atomised in the jet or delivered as a film along the surface. The liquid film formed at the channel surface as a result of deposition from the gas-droplet near-wall jet, or fed specially, is an effective means to enhance cooling. The structure of the near-wall flow and the efficiency of two-phase cooling are analysed based on available experiments. It is demonstrated that the combined gas and liquid film protection can be calculated as that for the laminar flow regime, and is the ultimate possible.

 

Author(s) Details

N.E. Shishkin
Kutateladze Istitute of Thermophysics, Siberian Branch, Russian Academy of Sciences, Novosibirsk, Russia.

 

Please see the book here:- https://doi.org/10.9734/bpi/psniad/v1/5585

Multi-vortex Impact of a Thermally Stratified Energy Deposition on a High-Speed Flow/Flight | Chapter 6| Current Research Progress in Physical Science Vol. 4

Numerical modeling of the effect of a thermally stratified energy source on the supersonic flow past a body “double-wedge - plate” has been conducted. Multiple generations of the Richtmyer-Meshkov instabilities were observed which caused the almost complete destruction of the bow shock front inside the source area and formed a new multi-vortex mechanism of the impact on the streamlined body. The defining parameters of the effect of stratified and homogeneous energy sources with equal values of the total energy are analyzed. The conducted calculations showed that the use of a stratified energy source, despite a small loss in the reduction of a drag force, gives an undoubted gain in reducing the temperature of a gas near the frontal surface of a body. It was found that redistributing the source energy into layers can significantly decrease the temperature at the vertex of the double-wedge and the average front surface temperature. Such an effect of a thermally stratified energy deposition could be used in the course of providing control over the parameters of a streamlined body during a high-speed flight.

 

Author (s) Details

 

O.A. Azarova
Federal Research Center “Computer Science and Control” of the Russian Academy of Sciences, Vavilova St. 40, 119333, Moscow, Russian Federation.

 

O.V. Kravchenko
Federal Research Center “Computer Science and Control” of the Russian Academy of Sciences, Vavilova St. 40, 119333, Moscow, Russian Federation.

 

Please see the book here:- https://doi.org/10.9734/bpi/crpps/v4/2679

Dynamics of Shock Structure and Frontal Drag Force in a Supersonic Flow Past a Blunt Cone under the Action of Plasma Formation: A Recent Study | Chapter 4 | Current Overview on Science and Technology Research Vol. 4

 The impact of a plasma generation on the supersonic flow through a body called a "blunt cone-cylinder" is investigated experimentally and via computational fluid dynamics (CFD) in this chapter. A sequence of Schlieren images of the non-stationary interaction between the bow shock wave and blast wave are obtained using high speed shadowgraphy. The Euler equation system serves as the foundation for the calculations that follow. The freestream has a Mach number of 3.1. A bounded gas volume with increased pressure undergoes an immediate energy explosion to depict the plasmoid. It has been investigated how a bow shock wave and blast flow interact to generate a shock wave structure. The enormous energy released to a supersonic flow (500J) enabled the production of a schematic illustrating the origin and dynamics of the succeeding shock waves and contact discontinuities, as well as a significant reduction in drag force and stagnation pressure (close to 80%). A low density and high gas temperature zone, which is the main element lowering frontal body drag force, was also studied in terms of its dynamics. For various plasmoid energy values, the dynamics of the front surface drag forces have been examined. The computational and experimental flow patterns were found to be qualitatively in agreement.

Author(s) Details:

Irina Znamenskaya,
Lomonosov Moscow State University, 119234, Leninskie Gory 1, Build 2, Moscow, Russia.

Vladimir Chernikov,
Lomonosov Moscow State University, 119234, Leninskie Gory 1, Build 2, Moscow, Russia.

Olga Azarova,
Federal Research Center, “Computer Science and Control” of the Russian Academy of Sciences, 119333, Vavilova Street 44, Moscow, Russia.

Please see the link here: https://stm.bookpi.org/COSTR-V4/article/view/8282

Study on Unsteady Triple-Shock Configurations in Supersonic Flows Past Combined Cylinder AD Bodies in Different Gas Media | Chapter 09 | New Approaches in Engineering Research Vol. 12

 The regulation of supersonic flows past aerodynamic bodies under the influence of external energy deposition is the subject of this research. The mechanism of a bow shock's interaction with an oblique shock coming from the bow shock's refraction at the external energy source surface is revealed. In this process, many types of shock waves may collide, including triple-shock configurations. The analysis of unsteady triple-shock configurations near the surface of combined cylinder bodies "hemisphere-cylinder" and "hemisphere-cone-cylinder" under the operation of external energy deposition and their effect on the body surface pressure are the goals of this paper. The calculations were carried out numerically using an inviscid technique based on the Euler equations at M=4 for gaseous mediums with specific heat ratios of 1.4 and 1.2. In the simulations, complex conservative difference techniques are applied. The angles of triple-shock arrangement have been shown to be dependent on the rarefaction degree in an energy source and the incidence shock angle. With rising boundary pressure, the generation of local space-time areas has been established. The activity of a vortex as well as the action of the originating shock segments in the region of a triple-shock configuration are shown to be linked in the mechanism of boundary pressure rise and local front drag force increase. A comparison with the symmetry of plane flow has also been made. The findings can be used to plan flow control using external energy deposition such as laser, microwave, or electrical discharge.

Author(S) Details

Olga Azarova
Department of Mathematical Modeling of Computer-Aided Design Systems, Federal Research Center “Computer Science and Control” of the Russian Academy of Sciences, Vavilova st. 40, 119333, Moscow, Russia.

Ludmila Gvozdeva
Department of Physical Gas Dynamics, Joint Institute for High Temperatures of the Russian Academy of Sciences Izhorskaya str. 13/2, 125412, Moscow, Russia.

Oleg Kravchenko
Department of Mathematical Modeling of Computer-Aided Design Systems, Federal Research Center “Computer Science and Control” of the Russian Academy of Sciences, Vavilova st. 40, 119333, Moscow, Russia.

View Book:- https://stm.bookpi.org/NAER-V12/article/view/3843

Study on Unsteady Triple-Shock Configurations in Supersonic Flows Past Combined Cylinder AD Bodies in Different Gas Media | Chapter 9 | New Approaches in Engineering Research Vol. 12

The regulation of supersonic flows past aerodynamic bodies under the influence of external energy deposition is the focus of this research. The interplay of a bow shock over a body with the oblique shock caused by the bow shock's refraction at the external energy source surface is revealed. Triple-shock configurations, for example, are one sort of shock wave intersection that could occur during this operation. The analysis of unsteady triple-shock configurations near the surface of combined cylinder bodies "hemisphere-cylinder" and "hemisphere-cone-cylinder" under the action of external energy deposition, as well as their effect on the body surface pressure, are the goals of this article. The calculations were carried out numerically using an inviscid approach based on the Euler equations at M=4 for gaseous media with 1.4 and 1.2 ratios of specific heats. The simulations employ sophisticated conservative difference techniques. The angles of a triple-shock arrangement have been shown to be dependent on the degree of rarefaction in an energy source as well as the incidence shock angle. With increased boundary pressure, local space-time areas can be generated. The activity of a vortex as well as the action of the originating shock segments in the region of a triple-shock configuration are shown to be linked to the mechanism of boundary pressure rise and local front drag force increase. A comparison with the symmetry of the plane flow has also been made. The findings can be utilised to plan flow control using external energy deposition techniques such as laser, microwave, or electrical discharge.

Author (S) Details

Olga Azarova
Department of Mathematical Modeling of Computer-Aided Design Systems, Federal Research Center “Computer Science and Control” of the Russian Academy of Sciences, Vavilova st. 40, 119333, Moscow, Russia.

Ludmila Gvozdeva
Department of Physical Gas Dynamics, Joint Institute for High Temperatures of the Russian Academy of Sciences Izhorskaya str. 13/2, 125412, Moscow, Russia.

Oleg Kravchenko
Department of Mathematical Modeling of Computer-Aided Design Systems, Federal Research Center “Computer Science and Control” of the Russian Academy of Sciences, Vavilova st. 40, 119333, Moscow, Russia.

View Book :- https://stm.bookpi.org/NAER-V12/article/view/3843