I am now using PHOENICS to solve for the pressure and velocity of an ideal flow past a cylinder. I tried to use body-fitted coordinate system but the result coming out is completely out. In the Cartesian coordinate system, I manage to solve it. I am novice in BFC and PHOENICS, I need some advice from you all. Thanks

Is the flow inviscid and two-dimensional ? If this is true, I can give you a small program which can deal with this problem.

to get specific advice on using Phoenics it is probably better to ask colleagues/coworkers who use it or to use your customer service (if you have that available to you)