Search

Numerical investigations of the asymmetry of a fluid flow in the channel of an air intake which is due to the interaction of a compression shock, generated by the shell ring of the air-intake channel, with the boundary layer on the longitudinally ribbed lower surface of this channel have been performed on the basis of the Reynolds-averaged Navier–Stokes equations and the SST k–ω model of turbulence. Data on the structure of the fluid flow in such a channel with a narrowing inlet part and a next part of constant cross section, the limiting flow lines on the longitudinally ribbed lower surface of the channel, and the profiles of the velocity of the flow and the total pressure in the boundary layer in the channel have been obtained for the case where the Mach number of the fluid flow incoming to the channel is M = 4. [ABSTRACT FROM AUTHOR]

The results of the numerical modeling of a flow with a pseudo-shock in an axisymmetric duct are presented. The duct included a frontal inlet with the initial funnel-shaped compression part and the cylindrical throat part as well as the subsequent expanding diffuser. To create a flow with a pseudo-shock, the duct was throttled with the use of the outlet converging insert. Numerical computations of the axisymmetric flow have been conducted on the basis of the solution of the Reynolds-averaged Navier−Stokes equations and with the use of the k-ω SST turbulence model. As a result of computations, such parameters of the flow were determined as the location of the beginning of the pseudo-shock, the length of its supersonic part, the velocity profiles in different cross sections of the pseudo-shock, the pressure distribution on the duct wall, the total pressure recovery factor, and others. The behavior of these parameters at the freestream Mach number М = 6 was analyzed versus the diffuser opening angle and different degree of the inlet duct throttling. [ABSTRACT FROM AUTHOR]

Aerodynamic design of an innovative supersonic three-dimensional air-intake including a starting device has been carried out. The intake concept is based on the use of an external compression ramp in the form of a caret wavefider. In a design flow regime, this ramp generates a plane oblique shock wave lying on its swept leading-edges and a subsequent two-dimensional isentropic compression wave. The intake starting is provided with a device special flaps of which in the throat are opened slightly in order to enlarge it and to form here both longitudinal and cross slots for air bleed and boundary-layer diversion. The same device can also serve for regulation of intake operating regimes depending on the flight velocity. The experimental model intake with a design Mach number MD) - 2 has been developed and tested at flow Mach numbers 1·5, 1·75, and 2·0 in the T-313 supersonic wind tunnel based at ITAM. Flow patterns about the intake have been observed, and flow parameters characterising the intake performance have been measured. The experimental results obtained have confirmed the workability of the starting/regulating device; the data on the efficiency of the model intake have demonstrated its good characteristics in terms of the total pressure recovery. [ABSTRACT FROM AUTHOR]

Waveriders with lower surfaces defined by power-law functions have been generated based on the flow behind planar oblique shock waves. Results of numerical simulation of the inviscid three-dimensional steady-state flow near the waveriders in off-design regimes are presented. A finite volume method is used to solve the Euler equations. The features of gasdynamic flow patterns near a compression surface are investigated with particular attention to the possibility to design configurations flown without inner shocks at regimes of freestream Much numbers larger than the design Mach values. The results were obtained at the freestream Mach numbers of 4, 5, 6, 6.5, and 8 and angles of attack up to 21 deg. The design Mach numbers of the waveriders studied are 4, 6, and 7. [ABSTRACT FROM AUTHOR]

Deals with a study on the aerodynamics of a type of waverider derived from supersonic axisymmetric flows inside constricting ducts. Design of convergent waveriders; Properties of the flows basic for convergent waverider designing; Characteristics of convergent waveriders.