38 research outputs found
Computational methods for vortex dominated compressible flows
The principal objectives were to: understand the mechanisms by which Euler equation computations model leading edge vortex flows; understand the vortical and shock wave structures that may exist for different wing shapes, angles of incidence, and Mach numbers; and compare calculations with experiments in order to ascertain the limitations and advantages of Euler equation models. The initial approach utilized the cell centered finite volume Jameson scheme. The final calculation utilized a cell vertex finite volume method on an unstructured grid. Both methods used Runge-Kutta four stage schemes for integrating the equations. The principal findings are briefly summarized
An embedded mesh procedure for leading-edge vortex flows
A cell-vertex scheme is outlined for solving the flow about a delta wing with M (sub infinity) is greater than 1. Embedded regions of mesh refinement allow solutions to be obtained which have much higher resolution than those achieved to date. Effects of mesh refinement and artificial viscosity on the solutions are studied, to determine at what point leading-edge vortex solutions are grid-converged. A macroscale and a microscale for the size of the vortex are defined, and it is shown that the macroscale (which includes the wing surface properties) is converged on a moderately refined grid, while the microscale is very sensitive to grid spacing. The level of numerical diffusion in the core of the vortex is found to be substantial. Comparisons with the experiment are made for two cases which have transonic cross-flow velocities
Research in computational fluid dynamics
The numerical integration of quasi-one-dimensional unsteady flow problems which involve finite rate chemistry are discussed, and are expressed in terms of conservative form Euler and species conservation equations. Hypersonic viscous calculations for delta wing geometries is also examined. The conical Navier-Stokes equations model was selected in order to investigate the effects of viscous-inviscid interations. The more complete three-dimensional model is beyond the available computing resources. The flux vector splitting method with van Leer's MUSCL differencing is being used. Preliminary results were computed for several conditions
Lean Aerospace Engineering
William Littlewood Memorial lecture at the 46th AIAA Aerospace Sciences meetin
Aircraft System Design Graduate Curriculum: A Lifecycle Focus
Aircraft system design encompasses technical, social and lifecycle topics, and is suitable for graduate studies at the masters level and beyond. Several degree programs in MIT鈥檚 School of Engineering offer opportunities for students seeking subjects and degrees in this area. These programs are summarized, and one subject on Aircraft Systems Engineering is introduced as an illustration of content and pedagogy addressing lifecycle topics. Based upon several years of experience of participation in these programs and in offering curriculum, the authors put forward seven observations to stimulate further dialog and progress on this topic
Designing and Deploying Lean Healthcare Curriculum
LAI Webinar Knowledge Exchange Event presentatio