Supersonic Flow Of Ideal Gas Research Articles

The choice of the system of geometric parameters of an optimized wing

A direct optimization method is used to determine the form of the wing which enables the aerodynamic performance to be improved for a given lift in the supersonic flow of ideal gas. The flow around the wing and its characteristics are calculated within the framework of a model based on Euler's equations. On the basis of a local analysis of the load distribution on the wing, a method is proposed for choosing the system of geometric parameters which ensures rapid convergence to the optimum. It is shown that one of the parameters of the system (the angle of rotation of the wing panel relative to the central chord) has a very slight influence on the aerodynamic characteristics of the wing.

Supersonic ideal-gas flow of in the throat region of a nozzle

The problem of profiling a supersonic nozzle with uniform outlet flow is considered when the contour is constructed from a point on a given convergent section of the nozzle. It is shown that there are contours such that the flow in the throat is supersonic in choked regimes (as distinct from common notions of mixed or uniform sonic flow). The influence of flow nonuniformity in the throat region on the thrust of a supersonic nozzle is analyzed.

Equilibrium of a flexible permeable shell in a supersonic gas flow

The plane steady-state regime of uniform supersonic ideal-gas flow around a uniaxial absolutely flexible open permeable shell is investigated numerically [1]. The effect of the angle of attack and the degree of nonuniformity of the permeability distribution on the aerodynamic characteristics and the equilibrium shape of the shell is determined for various methods of shell attachment. Approximate “localization relations,” which take into account the dependence of the distributed load on a concave permeable screen on its degree of permeability and the free-stream parameters, are formulated. An example of the application of these relations to the solution of three-dimensional problems of the equilibrium of permeable shells of the “circular dome” type in a supersonic flow [2] is given.

Combined method of calculating supersonic ideal-gas flow over a wing with a supersonic blunt leading edge

A combined numerical method, based on the successive calculation of the flow regions near the blunt leading edge and center of a wing, is proposed on the assumption that the angle of attack and the relative thickness and bluntness radius of the leading edge are small. The flow in the neighborhood of the leading edge of the wing is assumed to be identical to that on the windward surface of a slender body coinciding in shape with the surface of the blunt nose of the wing and is numerically determined in accordance with [1]. The flow parameters near the center of the wing are calculated within the framework of the law of plane sections [2]. In both regions the equations of motion of the gas are integrated by the Godunov method. The flow fields around elliptic cones are obtained within the framework of the combined method and the method of [3], A comparative analysis of the results of the calculations makes it possible to estimate the region of applicability of the method proposed.

Use of the curvature hypothesis for calculating supersonic flow past a rotating finned body

Three-dimensional supersonic ideal-gas flow past axisymmetric finned bodies rotating about the longitudinal axis is considered. A calculation method based on the numerical solution of the Euler equations by finite differences is described. The effect of the rotation of the body is taken into account within the framework of the curvature hypothesis [1], which provided that the dimensionless rate of rotation is small reduces the solution of the unsteady three-dimensional problem of supersonic flow past a rotating body to the solution of the steady-state problem of flow past a nonrotating body with specially curved fins. The problem of the rotation of a finned body in a free stream is solved.

Aerodynamic characteristics of long blunt cones with intense mass transfer

The effect of injection from the blunt surface on the aerodynamic characteristics of long blunt cones inclined at an angle of attack to a supersonic ideal-gas flow is numerically investigated.

Flow past blunt bodies with nose spikes and surface injection

Axisymmetric supersonic ideal-gas flow past a blunt body with a forward-projecting spike is numerically investigated with allowance for injection from the surface. The effect of the length and shape of the spike, the parameters of the injected gas and the position of the permeable zone on the flow pattern and drag is studied.

Stability of supersonic ideal-gas flow past cylindrical channels and cavities with a bow shock

Stability of supersonic ideal-gas flow past cylindrical channels and cavities with a bow shock

Numerical investigation of supersonic flow past blunt bodies with protruding spikes

A procedure for the calculation of a supersonic flow of ideal gas near axisymmetric blunt bodies with protruding spikes is developed. The flow past a frustum of a cone with a protruding spherically blunt cylindrical spike as a dependence on the ratio K of the spike length1 to the diameter D of the flat end of the body and the Mach number M of the oncoming flow is studied. Several steady flow regimes are obtained, including the formation of circulation zones and internal shock waves in the shock layer. It is shown that mounting a spike in front of the frustum of a cone can lead to a 40–50% reduction in its drag. A full investigation of the variation of the drag coefficient as a dependence on K is carried out for M = 3.

Distribution of radiant heat fluxes over the surface of three-dimensional and axisymmetric bodies in a supersonic ideal-gas flow

Numerous studies have been devoted to the calculation of supersonic radiating flow past bodies (see the bibliography in [1, 2]). In almost all these studies the gas flows investigated are plane or axisymmetric. Three-dimensional flows, however, have received little attention. The flow of air past three-dimensional bodies was considered in [3], where the chief object was to investigate the accuracy with which a real radiating volume can be simulated by the widely used plane-layer approximation. In [4] the flow of a hydrogen-helium mixture past three-dimensional bodies was investigated in the hypersonic approximation in the neighborhood of the stagnation point and in two planes of symmetry with allowance for the screening of the radiation of vaporized material.

Three-dimensional supersonic flow of ideal gas past a body with tail fins

The results are given of numerical and experimental investigations of the steady supersonic flow of an ideal gas past a model of a body with + and X fins. The angle of attack varied from 0 to 20 °. A study is made of the physical structure of the flow, and the pressure distributions, the coefficients of the normal force and the pitching moment of the complete body and the individual fins, and also the increment of the coefficient of the normal force acting on the body due to the influence of the fins are found. A comparison with linear theory and the experimental data is made. The agreement between the calculated results and the experimental data is satisfactory.

Wave resistance in supersonic ideal gas flow in nonlinear theory

Wave resistance in supersonic ideal gas flow in nonlinear theory