Measuring Coolant Flow Rate

[Frank]

Has anyone measured coolant flow rate in a pipe?

And I mean a closed system on a loaded (hot) engine....

What device did you use?
Were you on a dyno, or driving?
Was it any use? Accuracy? Reliability?

I see some expensive options, but I have the feeling someone has found the easy way before me.

Many thanks for those who provide advice.

Frank
UQ (Australia) 2001-2005

[jd74914]

How cheap is cheap? With a price range it's easier to suggest options. I've designed test stands for a number of applications (many of them super hot with pretty extreme transients) and you have a number of choices. Unfortunately, none are super cheap if you are looking for good accuracy.

If you watch for a bit you can get a used turbine flow meter from FTI off eBay for ~$150-200 which will work well. The nice thing about turbine meters is that they literally remain accurate for years unless the bearings have been cooked. They also have a small time constant so we can get good data from fast transients and are also really small so it's easy to find a place to put them.

Alternatively, its also possible to buy a differential pressure transmitter and measure across an orifice or venturi. Then you can calibrate with bucket test and do a correction for density/viscosity change due to temperature.

[Frank]

<$1000 would be good
<$200 would be fantastic

It's for a 200kW (ish) truck engine

I had consider an FTI, FT-20, 9-90GPM , 1" ID

I have no idea how much this would cost
I had also considered a cheap variable area flow meters and taking visual readings...
I had also considered a cumulative flow meter and taking a reading after a long run at a constant rpm..

My guess is that experience counts in this area, and I've met nobody with experience in these.... Maybe I need to venture into a chemical engineering lab at the local university?

[Frank]

Is there any other technology, ultrasonic or otherwise... that is commonly used?

[Mumpitz]

Euromag MUT4000
I believe its around $1-2000 USD for the sensor + transmitter. it's been a couple years since I was involved with the project that they were purchased for.

[jd74914]

Mag meters are pretty good too. I'd rank them right up there with turbines. For the application I don't think you could go wrong with either choice.

Ultrasonic meters are generally very expensive and even on the high end tend to be super finicky (intolerant of bubbles, weird flow patterns, etc.). Variable area meters are pretty cheap without analog outputs, but then you need to process the video, and there are not all that many designed for hot liquid flows.

FTI makes top of the line turbine meters, so they're likely going to be pretty expensive. Just a rough SWAG but with flow computer you're probably looking at about $2500+ (definitely email them for a price).

You can get cheaper stuff from Blancett (B1500 series, etc.; ~$1600 with flow computer) or even Omega. Something like the FTB-1431 with FTB-1400-MD computer is ~$1200 or FTB-107 is ~$1350 from Omega. If you can tolerate a frequency input you can save ~$400 in flow computer.

[Frank]

thankyou Mumpitz and jd74914 !