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The purpose of the study is to design economical shock tube. It is an instrument used for experimental investigations not only related to shock phenomena but also for the behavior of the material when it is subjected to high-speed flow. The material used here in this shock tube is stainless steel ss304 and aluminum. A shock tube consists of two sections, namely, the driver and the driven. The gas in the driven and driver is filled with atmospheric air and nitrogen, respectively, under the predominant condition.

The focus of the study is on the design and fabrication of shock tubes. a shock tube is a research tool to make an aerodynamic test in the presence of high pressure and temperature by generating moving normal shock waves under controlled conditions.

The main necessity for instrumentation in the shock tube experiment is to know the velocity of the moving shock wave from which the other parameters can be calculated. the pressure transducers are located in the shock tube in various locations to measure aerodynamic parameters in terms of pressure.

The main objective of this project work is to make an experimental setup to produce supersonic velocity with the readily available material in the market in a highly safe manner.

This paper describes a free‐piston driven expansion tube and its instrumentation. The facility is used to generate rarefied flows at speeds of approximately 10 km/s. Although the flow in the tube itself is in the continuum regime, rarefied flow conditions are achieved by allowing the test gas to further expand as a free jet into the facility's test section. The test flow is surveyed to provide bar‐gauge pressure measurements. Numerical simulation is then used to describe more fully the test flow properties. The flows produced are suitable for the aerodynamic testing of small models at superorbital speeds and should provide data that are suitable for the calibration of Direct Simulation Monte‐Carlo codes.

An axisymmetric shock-tube model of the high-pressure shock-tube facility at the Texas A&M University has been developed. The shock tube is non-conventional with a non-uniform cross-section and features a driver section with a smaller diameter than the driven section. The paper aims to discuss these issues.

Computations were carried out based on the finite volume approach and the AUSM+ flux-differencing scheme. The adaptive mesh refinement algorithm was applied to the time-dependent flow fields to accurately capture and resolve the shock and contact discontinuities as well as the very fine scales associated with the viscous effects. The incorporation of a conjugate heat transfer model enhanced the credibility of the results.

The shock-tube model is validated with simulation of the bifurcation phenomenon and with experimental data. The model is shown to be capable of accurately simulating the shock and expansion wave propagations and reflections as well as the flow non-uniformities behind the reflected shock wave as a result of reflected shock/boundary layer interaction or bifurcation. The pressure profiles behind the reflected shock wave agree with the experimental results.

This paper presents one of the first studies to model the entire flow field history of a non-uniform diameter shock tube with a conjugate heat transfer model beginning from the bursting of the diaphragm while simultaneously resolving the fine features of the reflected shock-boundary layer interaction and the post-shock region near the end-wall, at conditions useful for chemical kinetics experiments. An important discovery from this study is the possible existence of hot spots in the end-wall region that could lead to early non-homogeneous ignition events. More experimental and numerical work is needed to quantify the hot spots.

The purpose of this paper is to perform a computational fluid dynamics (CFD) simulation that is able to reveal what is happening for the shock wave generated by high speed flow test facility and to develop deeper understanding of all parameters which affect the shock wave velocity profile and pressure and temperature histories inside the facility.

Two dimensional time accurate Euler solver for shock tube applications was developed to simulate the flow process inside the shock tube. To ensure the ability of the CFD code to capture shocks, rarefaction waves and contact discontinuity and to produce the correct pressure, temperature, density and speed profiles, the code has been validated using two verification approaches. First, the code results have been compared to the Sod's tube problem (exact solution). Second, the code solution is compared with selected experimental measurements for a certain diaphragm pressure ratio.

Results presented in this paper show that after diaphragm rapture and when the shock did not reflect yet, the flow is symmetry and uniform in y‐direction. As the shock wave reflects from the tube end it will move to the left and interact with the discontinuity surface and the flow no longer symmetry. Results also show that two‐dimensional modeling of the high speed flow test facility is an effective way to obtain facility performance data. Although this paper focused on UNITEN's facility, the CFD code is generic and may be applied to other facilities. The present code showed good capability to provide the x‐t diagram successfully. From this diagram one can determine the useful duration (for this case it is about 10 ms), which is quite comparable compared to other facilities. It can be concluded, based on the agreement with the analytical results, that the numerical formulation for the inviscid part of the solver is valid.

This paper performs a CFD simulation that is able to reveal the shock wave behavior at high speed flow test facility.

THE development of a shock tube by the Department of Aerodynamics and Space Technology commenced in September, 1961, and was completed towards the end of 1962. The shock tube and the shock tunnel will fulfil two functions. They will serve primarily as teaching facilities, with post graduate courses in view and will also be used as an advanced tool for staff research.

The purpose of this study is to experimentally investigate the trends in shock wave Mach number that were observed when different diaphragm material combinations were used in the small-scale shock tube.

A small-scale shock tube was designed and fabricated having a maximum Mach number production capacity to be 1.5 (theoretically). Two microphones attached in the driven section were used to calculate the shock wave Mach number. Preliminary tests were conducted on several materials to obtain the respective bursting pressures to decide the final set of materials along with the layered combinations.

According to the results obtained, 95 GSM tracing paper was seen to be the strongest reinforcing material, followed by 75 GSM royal executive bond paper and regular 70 GSM paper for aluminium foil diaphragms. The quadrupled layered diaphragms revealed a variation in shock Mach number based on the position of the reinforcing material. In quintuple layered combinations, the accuracy of obtaining a specific Mach number was seen to be increasing. Optimization of the combinations based on the production of the shock wave Mach number was carried out.

The shock tube was designed taking maximum incident shock Mach number as 1.5, the experiments conducted were found to achieve a maximum Mach number of 1.437. Thus, an extension to further experiments was avoided considering the factor of safety.

The paper presents a detailed study on the effect of change in the material and its position in the layered diaphragm combinations, which could lead to variation in Mach numbers that are produced. This could be used to obtain a specific Mach number for a required study accurately, with a low-cost setup.

SHOCK tube measurement techniques require the use of instrumentation capable of sensing pressure variation across passing strong shock waves. The speed of shock wave passage along the shock tube is of the order of 6,000 to 7,000 ft./sec. while shock thickness is of the order of 0·1 in. This is calculated from the equation:—

The shock absorber is an important component of vehicle suspension that attenuates the vehicle vibration. Its running state directly affects the performance of the vehicle suspension. The purpose of this paper is to quantitatively study the relationship between damping characteristics and air chamber and oil properties in single-tube pneumatic shock absorber.

Combined with the principle of fluid dynamics and hydraulic transmission technology, the rebound stroke and compression stroke mathematical models, and damping characteristics simulation model are established to investigate the effect of the air chamber and oil property on damping characteristics.

Research results show that the initial pressure of the air chamber is the key parameter which influences the damping characteristics of the shock absorber. The change of the initial pressure has more impact on damping force, and less impact on the speed characteristic; the initial volume of the air chamber almost has no effect on the damping characteristics. The density and viscosity of the oil have certain influence on the damping characteristics. Therefore, selecting suitable damping oil is very important.

Using Matlab/Simulink software to build simulation models, its results are very accurate. The conclusions can provide a theoretical reference for the structure design of a single-tube pneumatic shock absorber.

When a reflected shock interacts with the boundary layer in a shock tube, the shock bifurcation occurs near the walls. Although the study of the shock bifurcation has been carried out by many researchers for several decades, little attention has been devoted to investigate the instability pattern of the bifurcation. This research work aims to successfully capture the asymmetry of the whole flow field, and attempt to achieve the instability mechanism of the shock bifurcation by a direct numerical simulation of the reflected shock wave/boundary layer interaction at Ma = 1.9. In addition, the reason for the formation of the bifurcated structure is also explored.

The spatial and temporal evolution of the shock bifurcation is obtained by solving the two-dimensional compressible Navier–Stokes equations using a seventh-order accurate weighted essentially non-oscillatory (WENO) scheme and a three-step Runge–Kutta time advancing approach.

The results show that the formation of shock bifurcation is mainly because of the shock/gradient field interaction, and the height of the bifurcated foot increases with the growth of the shock intensity and the gradient field. The unsteady asymmetry of the upper and bottom shock bifurcated structures is because of the vortex shedding with high frequency in the rear recirculation zone, which leads to the fluctuation of the recirculation area. The vortex shedding process behind the bifurcated structure closely resembles the Karman vortex street formed by the flow around the cylinder. The dimensionless vortex shedding frequency varies between 0.01 and 0.02. In comparison to the scenario at Ma = 1.9, the occurring time of instability is delayed and the upper and bottom bifurcated feet intersect in a relatively short time at Ma = 3.5. The region behind the bifurcated shock is a transitional flow field containing obvious cell structures and “isolated islands.”

This paper discovers an unsteady flow pattern of the shock bifurcation, and the mechanism of this instability in the reflected shock/boundary layer interaction is revealed in detail.

A higher-order implicit shock-capturing scheme is presented for the Euler equations based on time linearization of the implicit flux vector rather than the residual vector.

The flux vector is linearized through a truncated Taylor-series expansion whose leading-order implicit term is an inner product of the flux Jacobian and the vector of differences between the current and previous time step values of conserved variables. The implicit conserved-variable difference vector is evaluated at cell faces by using the reconstructed states at the left and right sides of a cell face and projecting the difference between the left and right states onto the right eigenvectors. Flux linearization also facilitates the construction of implicit schemes with higher-order spatial accuracy (up to third order in the present study). To enhance the diagonal dominance of the coefficient matrix and thereby increase the implicitness of the scheme, wave strengths at cell faces are expressed as the inner product of the inverse of the right eigenvector matrix and the difference in the right and left reconstructed states at a cell face.

The accuracy of the implicit algorithm at Courant–Friedrichs–Lewy (CFL) numbers greater than unity is demonstrated for a number of test cases comprising one-dimensional (1-D) Sod’s shock tube, quasi 1-D steady flow through a converging-diverging nozzle, and two-dimensional (2-D) supersonic flow over a compression corner and an expansion corner.

The algorithm has the advantage that it does not entail spatial derivatives of flux Jacobian so that the implicit flux can be readily evaluated using Roe’s approximate Jacobian. As a result, this approach readily facilitates the construction of implicit schemes with high-order spatial accuracy such as Roe-MUSCL.

A novel finite-volume-based higher-order implicit shock-capturing scheme was developed that uses time linearization of fluxes at cell interfaces.