Influence of second-order boundary layer effects in hypersonic flow over slender blunt cones

The aim of this study is to determine the influence of second-order effects in the aggregate on supersonic axisymmetric flow over slender blunt cones and also to determine the region of applicability of approximate methods of taking into account the strongest of these second-order effects — entropy layer absorption. A system of complete viscous shock layer equations containing all the terms of the gas dynamic Euler equations and all the second-order terms of asymptotic boundary layer theory is chosen as the gas-dynamic model. Within the calculation domain the problem is solved in a unified manner.Translated from Izvestiya Rossiiskoi Akademii Nauk, Meknanika Zhidkosti i Gaza, No.4, pp. 129–134, July–August, 1992.     

Numerical investigation of supersonic viscous gas flow over long blunt cones with allowance for equilibrium physicochemical effects

Supersonic axisymmetric viscous heat-conducting gas flow over long spherically biunted cones is considered over a broad range of Reynolds numbers on the basis of the complete system of viscous shock layer equations. An economical numerical method based on global iterations is used to solve the viscous shock layer equations. The general influence of the second-approximation effects of boundary layer theory and the influence of equilibrium physicochemical processes on the heat loads are determined for bodies with a large aspect ratio.Translated from Izvestiya Rossiiskoi Akademii Nauk, Mekhanika Zhidkosti i Gaza, No. 1, pp. 202–205, January–February, 1993.The author wishes to thank S. A. Vasil'evskii and I. A. Sokolova for providing the tables used to calculate the transport coefficients and G. A. Tirskii for his constant interest and useful discussions.     

On the applicability of some approximate similitude laws in hypersonic aerodynamics

The range of applicability of some similitude laws for heat transfer, friction and drag coefficients is discussed on the basis of numerical solutions of the complete viscous shock layer equations describing hypersonic flow past blunt bodies. Moscow. Translated from Izvestiya Rossiiskoi Akademii Nauk, Mekhanika Zhidkosti i Gaza, No.2, pp. 121–130, March–April, 1994.     

Application of the small-parameter method to the problem of the spatial flow of a viscous gas past bodies

The solution of the problem of the spatial hypersonic flow of a viscous gas past spherically blunted bodies is considered using the system of equations of a complete viscous shock layer (CVSL). The use of the small-parameter method (SPM) in conjunction with the method of global iterations enables one to reduce the computer time required by a factor of approximately 100 compared with the time needed to calculate similar problems in a strictly spatial formulation by establishment methods [1]. The flow past blunt cones and bicones of long length at low angles of attack is considered as well as the flow past a body, which differs slightly from an axisymmetric one, at zero angle of attack. The applicability of the SPM is confirmed by comparison with experimental and computed data.     

Rarefied gas flow through a pipe of variable square cross section into vacuum

The kinetic S-model is used to study the steady rarefied gas flow through a long pipe of variable cross section joining two tanks with arbitrary differences in pressure and temperature. The kinetic equation is solved numerically by applying a second-order accurate conservative method on an unstructured mesh. The basic quantity to be computed is the gas flow rate through the pipe. The possibility of finding a solution based on the assumption of the plane cross sectional flow is also explored. The resulting solutions are compared with previously known results.     

Active sound control in 3D bounded regions

We consider active sound control with the preservation of wanted sound in 3D bounded regions via numerical experiments. In contrast to some previous papers which are based on the difference potential method, our approach in the present work is based on surface potentials. In active sound control, some bounded domain is shielded from noise generated outside by situating additional sources at the perimeter of the domain to be protected. The method does not require knowledge of the source of noise (nature, location, and intensity). The approach allows the presence of wanted sound in the shielded domain, which is preserved, while the noise is canceled. To implement the method, the only required knowledge is the total acoustic field at the perimeter of the shielded domain. A number of test cases in different 3D bounded domain configurations are considered in the frequency domain. Furthermore, for the first time the effect of the number of secondary sources on the noise cancelation is studied. A significant level of volume noise cancelation is achieved at most parts of the shielded domain.     

A multithreaded OpenMP implementation of the LU-SGS method using the multilevel decomposition of the unstructured computational mesh

A new parallel version of the method LU-SGS (Lower-upper symmetric Gauss-Seidel) based on a multilevel decomposition of the unstructured computational mesh is proposed. The advantages of the proposed approach are demonstrated by computing the supersonic flow around the RAM-C geometry. The method is well scalable when a large number of threads are used on the processor Intel Xeon Phi.     

Effects of second-approximation of boundary layer theory in three-dimensional flow over bodies with a large aspect ratio at small angles of incidence

The influence of the second-approximation effects of laminar boundary layer theory on the heat transfer in three-dimensional hypersonic flow over blunt cones with a large aspect ratio is investigated numerically.Moscow. Translated from Izvestiya Rossiiskoi Akademii Nauk, Mekhanika Zhidkosti i Gaza, No. 2, pp. 57–64, March–April, 1995.