CFD (Computational Fluid Dynamics) / Flow Simulation Questions

[Jeffrey Meyer]

Some other problems I would love to use CFD for:

- determine if fiberglass fairings are worth the effort to construct in several areas. For example a wingtip.
- cowl design, or some simplified version of this
- heat flow in engine compartment after shutdown
- ducts and airflow for cabin heater
- ducts and airflow for air conditioner (I'm trying to put one in a Zenith, but that is another topic!)
- determine drag with/without wheel pants a different speeds

From your last point, it sounds like even assuming no prop, flow over the entire airframe would be impractical. What would the limit be, could a wheel with/without fairing be possible? !

Yes, it would certainly be possible, and a wheel with or without a wheel spat would be a very good exercise on the learning curve. I suggest you try 4 CFD test runs:
1. Wheel only.
2. Wheel with spat - external geometry only.
3. Wheel with truncated spat - see attached images.
4. Shell the spat (2mm say) with an opening for the wheel.

After you run the above do a quick estimation of the actual drag using the following formula:

Drag = 1/2 * rho * V^2 * Cd * S

where rho is the density of air (about 1.25 Kg/cubic meter), V is the velocity in m/sec, Cd is the drag coefficient (0.25 for the wheel only, 0.15 for the wheel with spat), and S is the frontal area of the assembly in square meters. Using these units drag force is measured in Newtons. 1 Newton = 98.1 grams = 0.216 lb.

I think you will be surprised by the difference between the CFD and the actual (theoretical) results, especially when you complicate this relatively simple geometry as in CFD run #4.

Looking forward to your comments.

[JohnMyers]

Thanks for your reply. I will start my SolidWorks journey and try not to learn things the hard way.

I infer from the above it won't be very accurate in the last case. What would you say is the most useful way to use SolidWorks for experimental aircraft, and what is more of a fools errand (simulating the whole aircraft)?

[JohnMyers]

Is flow simulation still supported in the new maker edition?

[JoeT]

Does the NEW SolidWorks for Makers include the Simulation software - i.e., CFD and FEA? The previous version did include the SIMULATION package.

Regards,
Joe T.