Military budget cuts and increased competition in the commercial market have shifted the focus of aircraft design to include affordability concerns. This has resulted in the need for increased knowledge in the early stages of design when a high percentage of the available resources are committed. The Technology Identification, Evaluation and Selection methodology outlined herein provides the de...

This paper describes the application of the leastsquares spectral element method to compressible flow problems. The method is described and results are presented for subsonic, transonic and supersonic flow problems over a bump.

SUMMARY Stetio pressure measurements have been made at subsonic Mach numbers to examine compressibility effects on a two-dimensional circular cylinder with two tangential blowing slots. These results together with forces derived from them are briefly discussecl.

The wake behind a circular cylinder in Mach 4 flow is examined experimentally in the Reynolds number range 2× 104 to 5× 105. Periodic oscillations of the sliplines in the wake are observed. The Strouhal number of the oscillations based on the diameter of the cylinder is found to increase monotonically from 0.30 to 0.50 with increasing Reynolds number. If the Strouhal number is formed using the ...

This work concerns the application of multi-objective evolutionary optimization by approximation function to 2D aerodynamic design. The new general concept of evolution control is used to on-line enriching the database of correct solutions, which are the basis of the learning procedure for the approximators. Substantially, given an initial very poor model approximation, which means small size o...

The application of proper orthogonal decomposition for incomplete (gappy) data for compressible external aerodynamic problems has been demonstrated successfully in this paper for the first time. Using this approach, it is possible to construct entire aerodynamic flowfields from the knowledge of computed aerodynamic flow data or measured flow data specified on the aerodynamic surface, thereby de...

We study a Riemann problem for the two-dimensional isentropic gas dynamics equations which models transonic regular reflection. When written in self-similar coordinates, the system changes type from hyperbolic to mixed hyperbolic-elliptic. Using the theory of one-dimensional hyperbolic conservation laws, we formulate a free boundary problem in the subsonic region and we outline the main ideas f...

1 School of Energy Science and Engineering, Harbin Institute of Technology, Harbin 150001, China; [email protected] (Y.J.); [email protected] (Y.-N.Z.) 2 Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing 100084, China 3 Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China; [email protected] 4 State Nuclear Power Technology R & D Cent...

In airframe technology, designs have become progressively more compact, to accommodate internal and external carriage by aircraft, launch tubes on warships or torpedo tubes in submarines. Propulsion has evolved from simple pulse jets, through turbojets and liquid propellant rockets or ramjets to the current mix of: turbojets for subsonic tactical cruise missiles, turbofans for subsonic strategi...

This research paper presents the CFD analysis of oscillating airfoil during pitch cycle. Unsteady subsonic flow is simulated for pitching airfoil at Mach number 0.283 and Reynolds number 3.45 millions. Turbulent effects are also considered for this study by using K-ω SST turbulent model. Two-dimensional unsteady compressible Navier-Stokes code including two-equation turbulence model and PISO pr...