jnelson33
Mechanical
- Mar 7, 2018
- 53
Please copy and paste my post if that assists responding.
I am trying to work backwards by selecting a target test chamber velocity to design a wind tunnel around. I want to revamp our current system as minimally as possible which means using the same fan and the current settling chamber and laminizer. The entrance and some of the test chamber section can be seen in this thread.
I understand all the area and pressure relationship stuff just fine. To me, deciding on the test section velocity by using the settling chamber and Bernoulli Principle equations seems partially erroneous since the laminizer is in there in the real world and affects free flowing air movement. The current setup has no entrance diffuser/section currently....this isn’t my design and I know it’s coefficients are wrong and its aerodynamics are questionable…
Regardless, this wind tunnel is used for heat exchanger studies, so that's why I'm looking to achieve a target velocity. 100 percent of the air is to be moved through the core for heat exchanger studies, and for that reason our test chamber now has the opportunity to be resized since it was designed incorrectly for the intended purpose.
Since this no doubt will require some fabrication work, I want to make sure the speed increase is viable (+10 MPH, currently 35 MPH). I'm probably just going to flow sim this in Solidworks, but I was also thinking I could just use the known test chamber speeds from our first tests to Bernoulli it out using the dimensions of the new, smaller cross section, higher speed test chamber. This method should be good for an estimate because it does not require my transition angles, correct? Do y’all know any other hacks like that?
Since I know Q (volumetric flow) of the fan and current dimensions of the test section and settling chambers transition, I’ve also got a sure fire way to roughly figure it out using advertised specs. But why on Earth is nobody teaching stuff this way? Why have the useless conceptual equations never been evolved and presented better for designing a wind tunnel??
I am trying to work backwards by selecting a target test chamber velocity to design a wind tunnel around. I want to revamp our current system as minimally as possible which means using the same fan and the current settling chamber and laminizer. The entrance and some of the test chamber section can be seen in this thread.
I understand all the area and pressure relationship stuff just fine. To me, deciding on the test section velocity by using the settling chamber and Bernoulli Principle equations seems partially erroneous since the laminizer is in there in the real world and affects free flowing air movement. The current setup has no entrance diffuser/section currently....this isn’t my design and I know it’s coefficients are wrong and its aerodynamics are questionable…
Regardless, this wind tunnel is used for heat exchanger studies, so that's why I'm looking to achieve a target velocity. 100 percent of the air is to be moved through the core for heat exchanger studies, and for that reason our test chamber now has the opportunity to be resized since it was designed incorrectly for the intended purpose.
Since this no doubt will require some fabrication work, I want to make sure the speed increase is viable (+10 MPH, currently 35 MPH). I'm probably just going to flow sim this in Solidworks, but I was also thinking I could just use the known test chamber speeds from our first tests to Bernoulli it out using the dimensions of the new, smaller cross section, higher speed test chamber. This method should be good for an estimate because it does not require my transition angles, correct? Do y’all know any other hacks like that?
Since I know Q (volumetric flow) of the fan and current dimensions of the test section and settling chambers transition, I’ve also got a sure fire way to roughly figure it out using advertised specs. But why on Earth is nobody teaching stuff this way? Why have the useless conceptual equations never been evolved and presented better for designing a wind tunnel??