Need Intake Advice On Flow Bench

[SlenderKen]

Hello all!

I have been making a flow bench for quite a while now and am stumped on the area around the orifice.
The airbox and fans are already finished, along with the fans.

So far here is what my bench looks like


The ABS tubing on the bottom (or the horizontal) is 3" and will be transitioning to a vertical tubing of 4".
My plans for the future are to have an ABS tubing above the orifice plate to act as a settling chamber.

My questions are:
1) How thick/large should the orifice plate be to measure the flow of an intake runner?
2) How would I test an injector angle? And how would it change my setup?
3) I want to include sensors to measure pressure and maybe flow. Where would be the optimal places to put them? And how many of them should I get? I want to get a digital readout, so if anybody can link me to a specific make or brand, that would be much appreciated!

I am very new to flow benches, so please bear with me!

[Tony]

Welcome to the Forum Ken.

Your picture did not show, so we are in the dark.

1/ The orifice plate is a flow measurement device, so it would be sized to generate a "sensible" pressure drop over the range of flows you are interested in measuring. If the pressure drop across the orifice is very low (orifice too big) there can be problems with accurately measuring such low pressure.
If the orifice is too small, there will be an excessive pressure drop across the orifice, which means whatever is providing the airflow source, will need to be much larger and more powerful than it needs to be.
There are no hard and fast rules, its all quite flexible, but the measurement orifice needs to have a suitable flow range to suit the application.
Big difference between a cart engine and a big block drag race engine.

2/ Injector angle has more to do with fuel pattern and combustion. Probably an engine dyno might be best tool for that.

3/ Pressure and flow of what exactly, oil, air, fuel, water ?

[SlenderKen]

Hello,

Thank you for your reply! I will be posting a picture of it when I get home.

I want to look mostly at the pressure and flow of air going through the intake runner, but I'm not sure how many/where the sensors should be placed.

[Tony]

The usual way to measure flow velocity in a port is with a Pitot probe. You can then move the probe around the port to get a flow profile. From that you can see which parts of the port has a lazy flow, and which parts have a velocity higher than the average.

Intake and exhaust ports obviously flow in opposite directions, so you need Pitot probes facing both ways.

Bruce (the guy that runs the Forum) makes some really nice flow probes.

[SlenderKen]

http://imgur.com/a/UDqLU

Would a digital manometer be optimal to use to measure the pressure of the flow before and after the orifice?

[Tony]

http://imgur.com/a/UDqLU

Would a digital manometer be optimal to use to measure the pressure of the flow before and after the orifice?

The best thing to use would definitely be the PTS Forum digital manometer. Its not just the manometer, but the very well developed software that goes with it.

That will also display port velocity with an appropriate Pitot probe.

[SlenderKen]

How many would I need// where would I place them?

Also, how much are they per unit?

[Tony]

Here is a link to the PTS digital manometer.
That comes with all the software to display test pressure, CFM, and port velocity on a lap top computer.
http://www.flowbenchtech.com/ptsdm.html

To use the port velocity feature you also need to get one or two flow probes. (one for intake, one for exhaust because they flow opposite directions)
And Bruce can also supply a measurement orifice, and one or more calibration orifices in whatever flow ranges you are interested in.
http://www.flowbenchtech.com/store.html

That is really all you will ever need for a complete fully equipped flow bench monitoring package.