On the basis of resonance theory the possibility of the longitudinal structures generation was fixed in the compressible boundary layer by an external vorticity. It takes place under a condition when parameters of externally vortex wave become the close to parameters of eigen stationary perturbations of a boundary layer. Researches are conducted as in case of subsonic numbers of the Mach, and i...

In this paper, we propose and study two time-splitting spectral methods for the generalized Zakharov system. These methods are spectrally accurate in space, second order in time, and unconditionally stable. The unconditional stability of the methods offers greater numerical efficiency than those given in previous papers, especially in the subsonic regime. Our numerical experiments confirm the a...

Scientific and Technical Information Office 1980 SUMMARY Systematic investigations were performed on a variety of probes to determine their potential for possible application as sensors attached to helicopter blades to measure both the instantaneous angle of attack as well as the dynamic head during actual flight operations. After some preliminary considerations a sensor of essentially spherica...

We discuss how the lower corona may be connected to the chromospheric network pattern throughmagnetic funnels at the boundaries of the chromospheric network. At the feet of these funnels are located thin ionizing layers. The steady-state flow and temperature structure in the funnels is analyzed on the basis of the continuity of downward electron heat flux from the coronal base and the upward ad...

A straightforward procedure has been developed to quickly determine an inviscid design of a hypersonic wind tunnel nozzle when the test gas is both calorically and thermally imperfect. This real gas procedure divides the nozzle into four distinct parts: subsonic, throat to conical, conical, and turning flow regions. The design process is greatly simplified by treating the imperfect gas effects ...

This paper concerns implicit large eddy simulations of subsonic flows through a symmetric suddenly expanded channel. We aim at shedding light on the flow physics relatively high Reynolds number 10 000, based inlet bulk velocity and step height channel, examine compressibility effects for two Mach numbers, Ma = 0.1 0.5. Comparisons with experimental measurements are provided. In addition, we inv...

Flutter is a phenomenon resulting from the interaction between aerodynamic and structural dynamic forces may lead to destructive instability. The on an oscillating airfoil combination of two independent degrees freedom have been determined. problem resolves itself into solution certain definite integrals, which identified as Theodorsen functions. theory, being based potential flow Kutta conditi...