I am interested in finding, or constructing an aerodynamic tool that can be used to predict force coefficients on 3d (lifting and non-lifting) arbitrary bodies. The emphasis of the tool is on robustness and speed of execution, and less-so on accuracy.

I assume that a grid-free method, such as a panel method is the way to go, and would really appreciate any references people could give me - are there any such models out there already?

There seems to be a huge amount of work done on aerofoils and slender bodes, but little on bluff shapes. Any help would be greatly appreciated.

Our SymLab Panel Flow add-on uses a 3D panel method suitable for simulating the flow around arbitrary (including bluff) bodies. To import and create geometry I'd recommend our SymLab Professional add-on, which also includes the panel method.

Full disclosure: I represent Symscape the SymLab developer.

And another option is PSW (Personal Simulation Works) from Aerologic: http://www.aerologic.com/index.html

(I'm not affiliated with Aerologic, just remember we had some students making their course projects with PSW)

There are a lot of such codes. But first, some clarification:

1) In my knowledge, panel methods are inviscid aerodynamic tools so there's no way to have good results if applied to bluff body, even if coupled with some inverse boundary layer code

2) Actually you can obtain forces only under some conditions which are a limit on the kind of arbitrary bodies you can apply the code

For these reasons these codes are usually used for slender bodies and incompressible flows.

Some of these codes, largely tested, are:

PMARC, USSAERO, PANAIR

There are also a lot of papers you can read about these codes and the panel method in general. Most of these are available at the nasa technical reports server:

http://ntrs.nasa.gov/search.jsp

for others you have to pay.

Some (very few, there is a huge amount of material on this topic) good references are:

Katz, Plotkin : Low Speed Aerodynamics, Cambridge

Hess : Panel Methods in Computational Fluid Dynamics, Annu. Rev. Fluid Mech. 1990

Hess, Smith : Calculation of Potential Flow about Arbitrary Bodies, Douglas Aircraft Company

Erickson : Panel Methods - An Introduction, NASA TP 2995

S. C. Smith : A Computational and Experimental Study of Nonlinear Aspects of Induced Drag, NASA TP 3598

D. L. Ashby : Potential Flow Theory and Operation Guide for the Panel Code PMARC_14, NASA TM-1999-209582

Also, if you want to implement a boundary layer model:

Mughal, Drela : A CALCULATION METHOD FOR THE THREE-DIMENSIONAL BOUNDARY-LAYER EQUATIONS IN INTEGRAL FORM

Cebeci, Kaups, Ramsey : A GENERAL METHOD FOR CALCULATING THREE-DIMENSIONAL COMPRESSIBLE LAMINAR AND TURBULENT BOUNDARY LAYERS ON ARBITRARY WINGS

But, the more you search the more you find...i worked on this topic for 6 months and every day i founded new material