АннотацияЦель.Для тела вращения со степенной образующей и сферическим, параболическим и гиперболическим затуплениями вычисляется сила сопротивления в газовом потоке

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ÝÔÔÅÊÒ ÈÇÌÅÍÅÍÈß ÇÍÀÊÀ ÏÎÄÚ¨ÌÍÎÉ ÑÈËÛ ÄËß ÑÒÅÏÅÍÍÛÕ ÒÅË ÂÐÀÙÅÍÈßГорелов С. Л

In this paper, we calculate the aerodynamic forces acting on a wedge and cone in a rarefied gas flow. It is proved that there is a half-opening angle of the wedge and cone for which, as this angle increases, the lifting force becomes negative at an arbitrary attack angle. For high-velocity flows, such an effect is shown to exist at an arbitrary Reynolds number.

The efficiency of the self-similar interpolation method is demonstrated with reference to the solution of the problem of heat transfer in a rarefied gas between two coaxial cylinders rotating relative one another. The analytical solution of the problem is compared with the results obtained by direct statistical simulation. The most interesting result is the energy flux nonmonotonicity and the reversal of its sign with variation in the Knudsen number.

The effectiveness of the self-similar interpolation method in its simplest form is demonstrated by solving the problem of a planar Couette flow in a rarefied gas between plates with different temperatures. An analytic representation of the solution is compared with the results obtained by the DSMC method. The most interesting result is the nonmonotonicity of the heat flow and the change in its sign accompanying the modification in the gas rarefaction, i.e., in the Knudsen number Kn.

A method of self-similar interpolation is given for an approximation of a solution using given asymptotic representations of various types on the bounds of a function definition range. The effectiveness of the method involved is demonstrated on problems of rarefied gas dynamics, namely, slow 2D flows of Poiseuille and Couette, and hypersonic flow around a simple-shape body.

A solution procedure based on computer-algebra methods is applied to the eigenvalue problem for the Rayleigh equation with the Blasius velocity profile. The procedure can be used to manipulate power series containing a large number of terms. An expression for the phase velocity of the lowest-order harmonic is obtained in the form of series in the wave-vector components. Representation of the series in terms of Pade approximants is considered with a view to improving their convergence.