Overcoming the challenges of high-speed aerodynamic tests using pressure control
Aerospace development and testing applications often require high flow rates to pressurize large volumes. One example is in gas reservoirs, where the reservoir must be pressurized prior to conducting high-speed aerodynamic tests.
A customer approached Alicat looking to pressurize a 200 L gas reservoir to 1000 PSIG. The gas held in the reservoir would then be quickly released into a high-speed wind tunnel via a rupture disc, producing a hypersonic flow with a high Mach number.
At such a high pressure, it can be challenging to quickly reach high mass flow rates due to valve limitations. This challenge can be circumvented by first using a high-flow bypass valve to pressurize the chamber, and then switching to a high-precision pressure controller to maintain pressure.
Solution: Custom dual hammerhead valve gauge pressure controller
For this application, Alicat designed a custom gauge pressure controller with side-by-side hammerhead valves. This device is capable of operating at pressures up to 1000 PSIG, with control response times under 30 ms.
The team was able to bring their reservoir pressure up to 1000 PSIG using two steps:
- Pressurize the reservoir chamber through a solenoid valve to 980 PSIG.
- Close the valve and finish filling the chamber using the Alicat PCDH-1000 PSIG controller.
This solution led to a highly responsive aerodynamic test process which was more streamlined than the original procedure. More importantly, it enhanced the reproducibility of the hypersonic wind tunnel experiments by providing a more consistent flow – and therefore a more consistent windspeed.