The 2-D aerodynamic flow simulator MicroTunnel from MicroCFD has received four minor version upgrades this year. The latest upgrade, Version 1.4, was released on 21 December 2001. Here a short summary of the major improvements that occurred within the last seven months:

Since Version 1.1, released in June, the MicroTunnel main window fits onto the more common XGA (1024x768) desktop. The SXGA (1280x1024) desktop resolution, required to run Version 1.0, was inaccessible to some users. The four contour maps in the general view were replaced by a single larger map for more detailed viewing.

Version 1.2 fixed the tunnel resolution at 800x600 and added an assembly coded and speed optimized flow solver (cfd.dll). Compared to previous versions, the program runs 6x faster on most Windows PC's, and up to 10x faster on a few select models (Quantex Notebook T-1411). Since the output map is also 800x600, one pixel on the display corresponds to exactly one finite volume cell in the flow.

In Version 1.3 a cut-cell algorithm was implemented, which better represents the surface boundary. As a result, the flow over slender shapes (airfoils) is now smooth, and the solution is much more accurate. Upon customer request, the maximum allowable flow Mach number was raised to M = 10, although ionization becomes a factor at hypersonic speeds (M > 5).

Version 1.4 added more flexibility in the Modify Shape control box. Shapes can now be moved throughout the tunnel with much greater accuracy and range. Upon request by a customer in the automotive industry, the bottom of the test section can be turned into a solid wall to simulate ground effect.

Whether or not you have downloaded MicroTunnel in the past, the new version (1.4) comes with another three-day trial period. No pre-registration is necessary. The download is free, and it is the full version. Just go to,

www.microcfd.com/download.htm

or for first-time visitors,

www.microcfd.com

Any questions, comments, or suggestions are always appreciated. I am planning to incorporate a load routine for a common CAD data file format such as DXF in the future. If anyone has any experience in creating a MicroTunnel shape file quickly and efficiently from a CAD drawing, please email me or post a response on this board.

Wishing you a happy and prosperous new year,

Axel Rohde