Solving the inverse boundary-value explosion problem using a modified solid-liquid model

An analytical solution is obtained for the inverse boundary-value problem of crater-forming explosion of a buried strip charge. The solution is obtained by the modified solid-liquid model. A particular case is examined. © 1993 Plenum Publishing Corporation

A boundary value problem of aerohydrodynamics in designing an axisymmetric body with jet blowout

A numerical and analytical method for constructing a shape of the axisymmetric body streamlined with jet blowout by the specified velocity distribution along its meridian section is proposed. The foundation of the method is the iteration process based on the solutions of an inverse problem in the plane case and a primal problem for the axisymmetric body. A program realizing the iteration process is set up and examples of numerical calculations are given. © Allerton Press, Inc., 2010

Construction of an airfoil with an irregularity in the flow

Using the method of quasisolutions for inverse boundary-value problems of aerohydrodynamics, a problem of constructing an airfoil was solved by the specified velocity distribution along the sought airfoil contour when there is an irregularity in the flow such as a vorticity source. The cases of a source (sink) and vortex are obtained as particular ones. The airfoils are constructed numerically and analytically and conclusions are made about an influence of the irregularity position and type on the shape and aerodynamic characteristics of the airfoil. © Allerton Press, Inc. 2009

Inverse boundary value problem of aerohydrodynamics for an axisymmetric body with blowing from an annular channel

A numerical-analytical method is developed for determining the shape of a streamlined with jet blowing axisymmetric body from a given velocity distribution along its meridional section. Numerical result examples are given. Forces, which are influence on axisymmetric body, are calculated. Comparisons of aerodynamic characteristics for bodies with different location of annular channel are carried out. © 2012 Pleiades Publishing, Ltd

Design of a subsonic airfoil with upstream blowing

The problem is solved of designing a symmetric airfoil with upstream blowing opposite to subsonic irrotational steady flow of an inviscid incompressible fluid. The solution relies on Sedov's idea of a stagnation region developing in the neighborhood of the stagnation point. An iterative solution process is developed, and examples of airfoils are constructed. The numerical results are analyzed, and conclusions are drawn about the effect of blowing parameters on the airfoil geometry and the resultant force acting on the airfoil. © 2007 Pleiades Publishing, Ltd

On the aerodynamic forces acting on an airfoil section with a penetrable region

Strict formulas for calculating the aerodynamic forces acting on a section of an airfoil with a penetrable region, through which a part of an external flow of an ideal incompressible fluid is sucked in, and on an airfoil section, from which a jet stream is blown out, in the case where these sections are in a steady-state flow without separation have been derived. Formulas for calculating the power expended for the realization of suction of a part of an external flow through an airfoil section and simultaneous blow-out of a jet stream from it are proposed. © 2006 Springer Science+Business Media, Inc

Maximization of the velocity circulation in a flow around a smooth contour with sources and sinks

The problem of lift maximization for a smooth closed contour of given length with point singularities (sources and sinks) placed in an inviscid incompressible flow is analyzed under the condition that the stagnation (zero-velocity) points lie on the contour. A mathematical formulation of the corresponding optimization problem is given. Its analytical solution is reduced to two simpler problems, which are investigated numerically in the general case. Some specific cases are considered. It is shown that the circulation reaches its maximum on a circumference when all sources merge into a single source and all sinks merge into a single sink. It is concluded that the lift increases in the presence of singularities in extremal flow regimes and at certain flow rates to values that cannot be attained for impermeable contours. Copyright © 2000 by MAIK "Nauka/Interperiodica"

Lift maximization for a smooth contour placed in flow with a vortex

For a smooth contour placed in an inviscid incompressible potential flow with a vortex, a contour shape and a vortex location are determined for which the lift coefficient is maximal. © 2010 Pleiades Publishing, Ltd

Use of active control for elimination of flow separation with estimation of energy costs

Problems were posed and solved concerning the aerodynamic computation of the flow past an airfoil with an active boundary layer control device used to prevent flow separation. A moving wall, suction, or tangential blowing in the boundary layer was used as a flow control device. The turbulent boundary layer was computed by directly solving the boundary layer equations using an implicit difference scheme with adaptive grid generation and the determination of the computational domain size. A software code was developed, and numerical simulations were performed taking into account the energy costs related to the flow control device. The numerical results showed that the active flow control devices can be used to prevent flow separation. © Pleiades Publishing, Ltd., 2009