I'm an undergrad student doing a project trying to simulate flow past a cricket ball. any idea where i can get an executable code (preferably in Matlab)for flow past a sphere ?

Why don't you try this site:

http://www.math.psu.edu/dna/CFD_codes.html

It has many free codes available and maybe you'll find what you are looking for (though you might need to make some modifications and assumptions, etc..).

At this site you have to chose for category: public domain and you'll be linked to a list of free codes, with some basic information about each code.

Cheers, Patrick Godon