The effect of multicomponent diffusion on supersonic flow of carbon dioxide past bodies

Different approaches are considered to the inclusion of multicomponent diffusion into numerical analysis of supersonic flow of carbon dioxide past blunt-nosed bodies. Calculation results are given, which illustrate the effect of diffusion processes on heat transfer to the surface of a space vehicle moving in the atmosphere of Mars.     

A comparison of plasma and thermal effects upon supersonic flow past aerodynamic bodies

Technical Physics Letters - The task of controlled variation of parameters of supersonic flow past a semicylindrical aerodynamic body is considered. The action of gas-discharge plasma on the flow...     

Interaction of a combination of bodies in supersonic flow. Interference and diffraction of shock waves in flow over two bodies of revolution

Results are presented of numerical investigations of three-dimensional supersonic flows in a disturbed region of jointly streamlined two identical bodies arranged in parallel which represent combinations of a cone with a semivertex angle of 20° and a cylinder with a fineness ratio of 5. Longitudinal flow over bodies has been studied numerically based on the Euler equation at a Mach number of incident flow equal to 4.03 and a zero angle of attack. The effect has been shown of the distance between the axes of models on the flow structure and disturbed and total aerodynamic characteristics of bodies. Calculated results have been compared with data of the physical experiment. __________ Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 79, No. 4, pp. 81–90, July–August, 2006.     

Effect of radiation on the supersonic flow of a viscous ionized gas past blunt bodies

The supersonic flow of a viscous monatomic ionized gas past blunt bodies is investigated. The effect of radiation on the field of flow and on the heat flux transmitted to the wall is shown.     

Slender-ship shallow-water flow past a slowly varying bottom

Summary The unsteady subcritical potential flow of a slender ship moving past a slowly varying bottom in shallow water is analyzed using the methods of matched asymptotic expansions and multiple scales. The hydrodynamic pressure field on the ship is obtained to second order in the slenderness parameter.On leave from Aerospace Engineering Department, University of Maryland, College Park, Maryland, USA.     

A uniformly valid solution for the three-dimensional inviscid supersonic flow past blunt bodies with strong compression in the shock wave

Summary An analytical uniformly valid approximate solution is developed for the steady threedimensional supersonic flow past blunt bodies. The inverse problem is investigated, i.e. the shock shape is prescribed. Viscosity and heat conduction are neglected. The approximation is based on two main assumptions: i) the density ratio across the shock is very small, ii) the pressure does not change its order of magnitude along a normal to the shock surface. The pattern of the streamlines projected on to the shock surface is calculated from an ordinary differential equation of second order by taking into consideration the pressure gradients. By evaluating two integrals the flow quantities and the streamlines are determined in the shock layer together with the body shape. The solution is also valid for sharp nosed bodies.The method is applied to paraboloidal or hyperboloidal shock shapes of various cross sections. Results are presented for the streamline projections in the entire flow field. The flow quantities and the streamline pattern in the shock layer are calculated in the symmetry plane of the flow field. The streamlines differ from the geodesics, i.e. the solution according to the Newtonian model. The flow quantities on the body and the body shape show good agreement with numerical results of the direct problem by Rusanov.With 10 Figures     

Numerical investigation of supersonic flow past blunt bodies of intricate shape at an angle of attack and slip angle

A supersonic flow of viscous homogeneous gas past blunt bodies of intricate shape at an angle of attack and slip angle is investigated numerically within the model of complete three-dimensional viscous shock layer using the time relaxation method. The main regularities are studied of the general structure of flow and of the distribution of pressure and heat flux along the surface. An analysis is performed of their dependence on the shape of the body, angle of attack and slip angle, Mach and Reynolds numbers, and on other determining parameters of the problem. The accuracy and range of validity of a number of approximate approaches to the solution of the problem are estimated.     

The energetics of flow through a rapidly oscillating tube with slowly varying amplitude

Motivated by the problem of self-excited oscillations in fluid-filled collapsible tubes, we examine the flow structure and energy budget of flow through an elastic-walled tube. Specifically, we consider the case in which a background axial flow is perturbed by prescribed small-amplitude high-frequency long-wavelength oscillations of the tube wall, with a slowly growing or decaying amplitude. We use a multiple-scale analysis to show that, at leading order, we recover the constant-amplitude equations derived by Whittaker et al. (Whittaker et al. 2010 J. Fluid Mech. 648, 83-121. (doi:10.1017/S0022112009992904)) with the effects of growth or decay entering only at first order. We also quantify the effects on the flow structure and energy budget. Finally, we discuss how our results are needed to understand and predict an instability that can lead to self-excited oscillations in collapsible-tube systems.     

A numerical analysis of the unsteady flow past bluff bodies

The paper describes in detail a relatively sophisticated numerical approach, using the Boundary Element Method in conjunction with the Discrete Vortex Model, to represent the complex unsteady flow field around a bluff body with separating shear layers. Important steps in the numerical analysis of this challenging problem are discussed and a performance evaluation algorithm established. Of considerable importance is the effect of computational parameters such as number of elements representing the geometry, time-step size, location of the nascent vortices, etc., on the accuracy of results and the associated cost.As an example, the method is applied to the analysis of the flow around a stationary Savonius rotor. A detailed parametric study provides fundamental information concerning the starting torque time histories, evolution of the wake, Strouhal number, etc. A comparison with the wind tunnel test data shows remarkable correlation suggesting considerable promise for the approach.     

Separated flow past three-dimensional bodies as a singular perturbation problems

This paper proposes a method for computing steady wake flows of an inviscid fluid over a three-dimensional body with polygonal cross-section and arbitrary plan-form. The method is based on the technique of matched asymptotic expansions, assuming a large aspect ratio. The far-field velocity potential is given essentially by a lifting line and a line source. The near-field, treated as two-dimensional, is solved by a suitable version of Tulin's double spiral vortex model which incorporates a downwash correction and an underpressure in the near-wake. The latter is related to the Reynolds number of the corresponding real flow using recent results by Tulin and Hsu and the authors. Numerical results for a few prototype problems (flat-plate airfoil with separation at both the leading edge and the upper surface, flat-plate win with full or partial spoiler) are presented. The method can be efficiently implemented on a parallel computer.     

Control of supersonic flow around bodies by means of a pulsed heat source

The influence of an external, pulse-periodic, energy supply source on the aerodynamic characteristics of a hemisphere positioned downstream is simulated. Pis’ma Zh. Tekh. Fiz. 23, 1–8 (May 12, 1997)     

On the problem of rarefied gas flow past blunt axisymmetric bodies

Shock layer separation in flows of rarefied gas past axisymmetric models is determined by interferometric methods. The form of the density jump is established.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 15, No. 5, pp. 843–846, November, 1968.     

On collocation schemes for integral equations arising in slender-body approximations of flow past particles with circular cross-section

A collocation method is presented for solving a singular integral equation of the second kind arsing in the slender-body approximation of viscous flow past slender bodies. When the spectral representation of the integral operator is explicitly known, the collocation method is shown to recover the spectrum of the continuous operator. The approximation error is estimated for two discretizations of the integral operator, and convergence is proved. The collocation scheme is validated for several test cases and extended to situations where the spectrum is not explicitly known.     

Jet flow past an ellipsoid of revolution by means of a laser doppler anemometer

We give the results of the experimental investigation of the flow of a blunt turbulent jet past an ellipsoid of revolution, without injection and with injection of a polymer solution into the boundary layer.Translated from Inzhenerno-Fizicheskii Zhurnal Vol. 34, No. 1, pp. 99–103, January, 1978.     

The effect of arbitrarily oriented hot jet on supersonic flow past a blunt body

We present the results of numerical simulations of the flow past a blunt body, from which an oriented thin hot jet of an ideal gas is emitted. The dependences of the flow regime and total aerodynamic characteristics of the blunt body on the angle of hot jet emission have been studied.     

Free convection boundary layer flow of a micropolar fluid past slender bodies

The transverse curvature effects on axisymmetric free convection boundary layer flow of a micropolar fluid past vertical cylinders are investigated using the theory of micropolar fluids formulated by Eringen. The governing equations for momentum, angular momentum and energy have been solved numerically. Missing values of the velocity, angular velocity and thermal functions are tabulated for a wide range of the material parameters, transverse curvature parameter and Prandtl number of the fluid. A comparison has been made with the corresponding results for Newtonian fluids. Micropolar fluids display drag reduction and reduced surface heat transfer rate as compared with Newtonian fluids.     

Cyclic thermal creep model for the bodies of revolution

The new method of solving thermal creep problems, accounting for cyclic variations of external force and thermal fields was put forward. Asymptotic expansions and period averagings were used to derive the systems of basic and auxiliary equations. The equation of state for cyclic thermal creep was proposed and validated. Numerical simulation of the creep of cylinders under cyclic temperature variations was carried out.     

The flow past a spinning sphere in a slowly rotating fluid at small reynolds number

The axisymmetric flow due to a uniform stream at infinity past a slowly rotating sphere in a viscous incompressible rotating fluid is studied and the results are presented mostly in the form of graphs of the streamlines. A region of reversed flow and vortex formation is found to occur near the front or rear stagnation points under certain conditions depending upon the speed of the uniform stream at infinity, the radius of the sphere and the angular velocity of the sphere. The fluid may rotate in the same or opposite directions.     

Dissociated gas flow in the boundary layer along bodies of revolution of a porous contour

This paper studies the ideally dissociated gas flow in the so-called frozen boundary layer on bodies of revolution. The contour of the body of revolution is porous. The governing boundary layer equations are brought to a generalized form. The obtained equations are numerically solved using the finite differences method. Based on the obtained solutions, distributions of physical quantities in the boundary layer are presented in the form of diagrams. Conclusions on behaviour of these quantities are also made.