The flow field characteristics downstream of the evaporative flameholder in subsonic–supersonic mixing were experimentally investigated. study focused on examining effects different inlet static pressure ratios characterized by supersonic and subsonic parameters. results indicated that increase ratio enhanced fragmentation multiple vortices located mainstream. It also exacerbated asymmetry reci...

This paper examines the use of a hypersonic bi-directional flying wing concept for use in a high efficiency hypersonic system. The bi-directional flying wing concept consists of a symmetric planform which enables flight to occur at two different geometric configurations. The subsonic configuration would have a high aspect ratio and a low sweep. The aircraft would then rotate 90 degrees and ente...

A flight test evaluation of the performance-seeking control (PSC) algorithm on the NASA F-15 highly integrated digital electronic control research aircraft was conducted for single-engine operation at subsonic and supersonic speeds. The model-based PSC system was developed with three optimization modes: minimum fuel flow at constant thrust, minimum turbine temperature at constant thrust, and ma...

An overview of recent experimental results on instability and dynamics of jets at low Reynolds numbers is given. Round and plane, macro and micro jets are under the consideration. Basic features of their evolution affected by initial conditions at the nuzzle outlet and environmental perturbations are demonstrated.

A field trial was conducted to test the existence of subsonic (Vp < 331 m/s) P-waves previously reported in the literature. A 1-m-long reverse profile was acquired with three-component (3C) geophones on a sandy silt (unified classification ML). The silt had a porosity of 54%, a degree of water saturation of 63%, and a plasticity index of 10. No subsonic P-waves were observed, although highfrequ...

In this paper, we study irrotational subsonic and subsonic-sonic flows with general conservative forces in the exterior domains. The indicate new Bernoulli law naturally. For case, introduce a modified cut-off system depending on which needs varied Bers skill, construct solution by variational formula. Moreover, comparing previous results, our result extends pressure-density relation to case. A...

André V. G. Cavalieri, Peter Jordan, Tim Colonius and Yves Gervais Journal of Fluid Mechanics / Volume 704 / August 2012, pp 388 ­ 420 DOI: 10.1017/jfm.2012.247, Published online: 03 July 2012 Link to this article: http://journals.cambridge.org/abstract_S0022112012002479 How to cite this article: André V. G. Cavalieri, Peter Jordan, Tim Colonius and Yves Gervais (2012). Axisymmetric superdirect...

We study the subsonic flows governed by full Euler equations in the half plane bounded below by a piecewise smooth curve asymptotically approaching x1-axis. Nonconstant conditions in the far field are prescribed to ensure the real Euler flows. The Euler system is reduced to a single elliptic equation for the stream function. The existence, uniqueness and asymptotic behaviors of the solutions fo...

A simplified model problem is used to illustrate some of the parameters controlling the radiation of sound into an ambient medium due to the growth and subsequent decay of subsonic travelling waves, such as may occur via non-linear interactions in turbulent free shear flows. It is shown that substantial sound may be generated by apparently subsonic modes as a result of their growth and decay ch...

In this short note we study the model of subsonic detonation introduced by Sivashinsky. The model is described by the system of reaction-diffusion equations involving temperature, pressure and concentration of deficient reactant. It is shown that initial data with small support lead to quenching (decay of solution). In contrast, initial data with support large enough lead to propagation with fi...