I'd like to run some thrust tests on the bench, anyone have the hookup on a setup that's a bit more accurate than the "Wal-Mart fish scale"?

Also, I'm looking for conversion data for ambient vs standard temp and pressure........

Oli?


Thanks, Don.

Can't help you on the fish scale... If you figure a good one let us know !!!! I have a great test stand that slides on ball bearing rails, but the scale is a Walmart dial type... Not too accurate...
As far as the conversion deal, download this program and keep it on your desktop... Been useing it for years. Easy to use. You can convert anything !!!! Seconds to Light Years, Grams to Tons.... you name it !!!!!

http://wscope.com/convert.htm

Danno

I appreciate the input but that's not the sort of conversion I was looking for. Have that on my iPhone

I need to convert X lbs thrust on a day of Y temp and Z atmospheric pressure to X (corrected) lbs on a 59f (15c) day at 29.92", otherwise known as a 'standard day'.

This is how apples are compared to apples when testing in varying conditions which affect engine thrust.

Thx again tho,

Don.

You need a Density Altitude caculator... ???? I have one of those on a Jeppesen Flight calculator I have, but I'm not sure how you will corrolate thrust values... ??? I know what you are trying to do... I'm gonna have to backwards think on this !!!! I'll get back to you if I get a brainstorm... It seems if you know what the thrust value is at 29.92 , 59F at sea level, the you should be able to calculate precentage of performance lost due to Density Altitude increase, but converting that to lbs of thrust is what I'm not sure how to do... It's not going to be a linear scale I would think... All Performance charts I have seen and used have a curve that becomes more aggresive as the altitude increases... .... I think all the BS I have been saying is somewhat true... Keep me posted !!!!

Danno, Intrested and Confused !!!!

LOL, that makes two of us. Ur onto exactly what i'm trying to figure out........

I may pm Oli from RCJI and ask him since they do this a lot.

YepGreat little program. Have it and use it daily. Well worth the download.

My simple setup

Google "Force gauges" and you will find plenty of them.
Omega instruments makes a fine one.

Sweet! What a useful program! [8D]

Shaz

Don

http://www.scalesandbalances.co.uk/a...rce_Guage.html

I have an excellent Sauter gauge and a simple stand with a trolley that pushes against the gauge. The gauges measure in lbs Kg or Newtons.

Hope this helps.

John

Google "engine correction factors", "dyno correction factors", or "SAE J1349". There are several websites that walk through the formulas and/or have programs to correct for air density. SAE J1349 is the standard used in the automotive industry to correct automotive engine horsepower and torque data to standard conditions. These same correction factors should also be applicable to turbine thrust.

Here's one I found that seems easy to use: http://www.csgnetwork.com/relhumhpcalc.html

There may be slightly different methodologies used in the aircraft industry, but this should work for your purpose.

Joe

I had been playing the 'google game' before starting this thread but was asking the wrong questions, I think.

Thanks guys, I feel like Ive got some good starting points.

Oops. Googling 'force guages', all I seem to find are units costing $600 and up !