From saleh@npac.syr.edu Thu Nov 5 15:39 EST 1998 Received: from carver.npac.syr.edu (carver.npac.syr.edu [128.230.8.140]) by postoffice.npac.syr.edu (8.7.5/8.7.1) with ESMTP id PAA22858; Thu, 5 Nov 1998 15:39:09 -0500 (EST) Date: Thu, 5 Nov 1998 15:39:09 -0500 (EST) From: Saleh Elmohamed To: Bryan Carpenter cc: Saleh Elmohamed Subject: The CFD Demo Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Content-Length: 2062 Status: ROr Bryan, Here is a summary. Modify or add to it if you wish. If you like more details, let me know and will send some more: ------------------------------------------------------------ Computational Fluid Dynamics : 2-D Inviscid Flow, Airfoil, and Elliptic Flow Simulations This CFD system simulates a 2-D inviscid flow through an axisymmetric nozzle, flow over airfoil as well as an elliptic flow. The simulation yields contour plots of all flow variables, including velocity components, pressure, mach number, density and temperature. The plots show the location of any shock wave that would reside in the nozzle or at the tip of the airfoil. The simulation centers around finding the steady state solution to the 2-D Euler equations. For this, it uses a 4-stage Runge-Kutta time-stepping algorithm and a finite volume central-difference method to come up with the solution. At each stage, the residual is multiplied by a difference value. Generally, this gives a bit more accurate results since it goes over more than one stage. A numerical dissipation model is employed to dampen any spurious oscillations and prevent the solution from blowing up in the presence of shock waves (see James et al. 81). The dampening order is set by computing the even derivatives (i.e. 2nd and 4th) and then setting the order proportional to this. The flow is from left to right across the nozzle or over the airfoil. To see the flow through, 'tuft' and 'grid' keys were added. The flow shown here is transonic and the system can be adjusted to have either a subsonic or a supersonic flow. References: 1. "Numerical Solutions of the Euler Equations by Finite Volume Methods Using Runge-Kutta Time-Stepping Schemes," A. Jameson, W. Schmidt, and E. Turkel, paper no: AIAA-81-1259, AIAA 14th Fluid and Plasma Dynamics Conference, June 23-35, 1981, Palo Alto, CA, USA. 2. Monograph in CFD, T. Q. Dang, Dept. of Mechanical, Aerospace and Manufacturing Engineering, Syracuse University, Syracuse, NY, USA, 1997. From saleh@npac.syr.edu Thu Nov 5 16:26 EST 1998 Received: from carver.npac.syr.edu (carver.npac.syr.edu [128.230.8.140]) by postoffice.npac.syr.edu (8.7.5/8.7.1) with ESMTP id QAA23454 for ; Thu, 5 Nov 1998 16:26:24 -0500 (EST) Date: Thu, 5 Nov 1998 16:26:23 -0500 (EST) From: Saleh Elmohamed To: Bryan Carpenter Subject: Re: The CFD Demo (edit) In-Reply-To: Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Content-Length: 373 Status: RO The 'grid' key is not meant to show the direction of the flow, only the 'tufts' key. So that paragraph becomes: > [...] > The flow is from left to right across the nozzle or over the > airfoil. To see the flow through, a 'tuft' key was > added. The flow shown here is transonic and the system can be adjusted to > have either a subsonic or a supersonic flow. > > [...]