Video: Ride along with Stevo during the Gold Race

[Coyote Chris]

Re: Video: Ride along with Stevo during the Gold Race

Hey Michael, how does the TAS vary in a pitot-static system as the AOA increases? Any big change?

Here's cockpit footage with an overlay of some of the telemetry data from Sunday's Gold Race. It was a bumpy ride. Enjoy!

Note: the GPS receiver gives some erroneous data points above 3 G's. It's older tech and not designed to do what we're doing with it. Thus, I would trust the TAS on the right column for better average speeds. It's reported from the pitot-static system. GPS will give reasonable results for straight line data (Valley of speed and pylon 2-4).

Michael

https://vimeo.com/75721498

[Mluvara]

Re: Video: Ride along with Stevo during the Gold Race

Hey Michael, how does the TAS vary in a pitot-static system as the AOA increases? Any big change?

I can't see any major difference at this point, but to be honest, I haven't looked that deep. When I was crewing on 232, we noticed that the airspeed data from the telemetry appeared to show the aircraft speeding up going into the turn. Well, that wasn't the case. Turns out that under g load, the airspeed sensor's internal diaphragm would deflect under load and give us about 5mph extra indicated. I turned the sensor's axis 90 degrees and that issue went away.

Michael

[Mluvara]

Re: Video: Ride along with Stevo during the Gold Race

I was wondering about the propellor tip speed, too, but it's too late to find the equation and do the math.

Other thoughts: Stevo is a very talented pilot.

And thanks to the Michael and the entire team for the video and for the technology to allow us to ride along.

It's the sum of the square of the velocities SQRT(forward velocity^2 + tip velocity^2).

Good reading (based for R/C models, but same basic theory). http://www.supercoolprops.com/articles/transonic.php

The Cornell engine in RB ran like a scalded cat at 3100, Actually found that it worked better as 3200 put the prop tips close to supersonic.

You might just be seeing increased speed because of increased HP. Raising the RPM will raise the boost out of the supercharger. Putting the prop tips closer to mach is usually more inefficient.

Michael

[R/C Voodoo]

Re: Video: Ride along with Stevo during the Gold Race

Great videos of a great plane and pilot. Thanks for posting if you have more please post them. Thanks Jody

[ChrisMX105]

Re: Video: Ride along with Stevo during the Gold Race

It's the sum of the square of the velocities SQRT(forward velocity^2 + tip velocity^2).

Good reading (based for R/C models, but same basic theory). http://www.supercoolprops.com/articles/transonic.php



You might just be seeing increased speed because of increased HP. Raising the RPM will raise the boost out of the supercharger. Putting the prop tips closer to mach is usually more inefficient.

Michael

Guess I wrote it in a convoluted fashion, RB ran better at 3100 RPM than 3200 RPM, the 100 RPM increase brought the prop tips close to supersonic and actually had negligible if any performance increase. Extra boost from the 100RPM was not needed.