Thermal Imaging of an Amateur Bi-Propellant Rocket Engine

[eerocketman]

Hi everyone,

I am trying to accomplish what i wrote in the title. My university student org would like to acquire thermal data of our latest rocket engine during a static fire. The teams current approach is to throw on about 10 thermo-couples onto the engine and record temperature data like that. I was wondering if thermal imaging would be a better approach to this problem. We are worried that the sharp temperature gradient of about 1700 K. Can this still be done? Which sort of camera would we have to use? Any advice is appreciated! Thank you! Please let me know if you would like any more details of our system. Will post results here if successful (:

EDIT: I should mention we are primarily interested in the actual engine surface temperatures (which shouldn't exceed 200 C) not so much the flame. I am worried the flame will make data acquisition hard.
-Ali

[Spirit532]

You'll need a camera with a high temperature option and physical filter, of which I'm afraid there aren't many in the low-cost portion of the market.
500C is doable with any FLIR Exx and Txxx series camera that has the 0-650C optional range, and I believe they also offer a 1200C extension option. That should be your best bet.

[eerocketman]

UCSD Actually (:

[todd_fuller]

Keysight still has some 1200C thermal cameras for sale on eBay for ~$900. There is a thread related to this camera on here.

Refresh rate might be a consideration for any thermal camera. Not sure how long your burn will be or what part of the burn you're most interested in, but most thermal cameras aren't going to be able to capture anything high speed, or short duration.

[Vipitis]

Have you considered renting high end science cameras with very high refreshrate and radiometric video?

[mahony]

I guess you are not expecting 1700°C on the rocket body but for the plume only but 1700°C gas temperature will never translate to that high reading on a thermal camera due to very narrow emission compared to a black/grey body (as the rocket body is) and transmission too. This is especially true if you are going to use the LWIR band (8-14µm) but to a lesser extend also in the MWIR (3-5µm).

So if you are only interested in measuring the rocket engine solid parts temperatures you might be fine with most any reasoably good thermal camera that is good up to 500°C. Totally different story though if you are interested in exhaust gas temperature or even radiance measurements.