Saturday, February 13, 2016

Love for Fighters

My love for aircrafts and fighter planes was altogether put into a completely different level during my Under Graduation days. All thanks to my friend Mr. Neil Mehta, this guy since then has been a source of motivation for me and many others as well. This one is for you buddy.

The Sukhoi Su-30MKI (NATO reporting name: Flanker-H) is a twinjet multirole air superiority fighter developed by Russia's Sukhoi and built under licence by India's Hindustan Aeronautics Limited (HAL) for the Indian Air Force (IAF). A variant of the Sukhoi Su-30, it is a heavy, all-weather, long-range fighter. (source wiki).

GrabCAD has been my best source for finding CAD models and it never disappoints me. The actual CAD model was quite big so I had to scale it down to fit the geometry in my domain and mesh it.

Actual CAD geometry : GrabCAD
snappyHexMesh_1


snappyHexMesh_2
Finally simulations were complete. Presenting to you Flow over an Sukhoi Su 30 MKI  with Streamlines.

Streamlines over Sukhoi Su 30 MKI

Thursday, February 11, 2016

OpenFOAM Simulation of flow past FERRARI F 50

snappyHexMesh proves to be a big boon when you have a CAD file ready. Yesterday I tried to study the external aerodynamics of flow past a FERRARI F 50. To get CAD files use this website ( https://sites.google.com/site/garcfd/stl ), you can find some cool CAD files.



I would like to share some of the important things I learnt  while using snappyHexMesh utility.

1. Always use a ".stl" CAD file. Check for any holes in it, if any close them as this can cause issues later while running snappyHexMesh. ( basically a CAD clean up is always good)

2. Use a simple name for your CAD file. Do not name it too complex since we need to use this name multiple times in snappyHexMeshDict file. ( eg, car.stl - short and simple)

3. When you run the case always keep Allrun and Allclean script files ready. This will help you to save time while running the simulations.

4.Finally the most important point. When we create a blockMeshDict file please see to it that the size of the mesh should be uniform in X, Y and Z direction i.e. uniform cube.

Solver : simpleFoam ( implicit solver for incompressible and turbulent flow)

Domain size : 20m X 8m X 8m

 After snappyHexMesh


Velocity Contour : StreamLines






The simulation finally end, and they end quickly since its an implicit solver. For more details please post your comments here.