The current study presents the results of the aerodynamic noise prediction of the flow field around a NACA 0012 airfoil at a chord-based Reynolds number of 100,000 and at 8.4 degree angle of attack. An incompressible Large Eddy Simulation (LES) turbulence model is applied to obtain the instantaneous turbulent flow field. The noise prediction is performed by the Ffowcs Williams and Hawkings (FW-...

the effect of a transverse magnetic field on the boundary layer flow and heat transfer of anisothermal stretching cylinder is analyzed. the governing partial differential equations for themagnetohydrodynamic, temperature, and concentration boundary layers are transformed into a setof ordinary differential equations using similarity transformations. the obtained ordinarydifferential equations ar...

The effect of a transverse magnetic field on the boundary layer flow and heat transfer of anisothermal stretching cylinder is analyzed. The governing partial differential equations for themagnetohydrodynamic, temperature, and concentration boundary layers are transformed into a setof ordinary differential equations using similarity transformations. The obtained ordinarydifferential equations ar...

Pseudospectral methods are investigated for singularly perturbed boundary value problems for ordinary diierential equations which possess boundary layers. It is well known that if the boundary layer is very small then a very large number of spectral collocation points is required to obtain accurate solutions. We introduce here a new eeective procedure, based on coordinate stretching and the Che...

In this paper, we study the asymptotic behavior of the circularly symmetric solution to the initial boundary value problem of the compressible non-isentropic Navier-Stokes equations in a two-dimensional exterior domain with impermeable boundary condition when the viscosities and the heat conduction coefficient tend to zero. By multi-scale analysis, we obtain that away from the boundary the comp...

AC resistivity measurement results on Mn-Zn sintered ferrite were analyzed in the 0.1-500 MHz range. From electrical point of view, the material could be represented by an equivalent circuit of parallel resistance-capacitance cells connected in series corresponding to the contributions from bulk grains in one hand, and grain boundary layers in the other hand. The experimental resistivity curves...

In this article, we demonstrate how one can improve the numerical solution of singularly perturbed problems involving multiple boundary layers by using a combination of analytic and numerical tools. Incorporating the structures of boundary layers into finite element spaces can improve the accuracy of approximate solutions and result in significant simplifications. We discuss here convection-dif...

The numerical technique called upstream differencing, applied to mobility terms in Darcy’s law for steam and liquid flow in the geothermal simulators TOUGH and MULKOM, is shown to lead to numerical boundary layers in the equations for steady vertical steam-liquid counterflow. These boundary layers are found to be very narrow, and to act in the same way as capillary boundary layers, providing re...

This paper performs Direct Numerical Simulation of transition induced by blowing and suction in a spatially evolving Mach 2.25 supersonic boundary layer. We use a novel algorithm (Park & Mahesh 2007) capable of solving compressible flow on unstructured grids. Our objective is to evaluate our unstructured capability to simulate supersonic transition. Transition is achieved using controlled perio...

A grid free method for approximating incompressible boundary layers is introduced. The computational elements are segments of vortex sheets. The method is related to the earlier vortex method; simplicity is achieved at the cost of replacing the Navier-Stokes equations by the Prandtl boundary layer equations. A new method for generating vorticity at boundaries is also presented; it can be used w...