The purpose of the avionics flow balance test is to define the orifice sizes for each avionics line that result in adequate cooling flow to each avionics box over the entire flight envelope. This test is divided into two parts. The first part of the test is intended to define the test facility configuration that best matches the pressure drop characteristics of each avionics box. This test procedure is repeated as many times as necessary until the desired pressure drop characteristics is achieved. The second part of the test is intended to size the orifices for each avionics line. This test is also repeated as many times as necessary until the desired avionics flow balance is achieved.
In this paper, the author attempted to define the B aircraft avionics flow balance test procedure through reviewing the A aircraft avionics flow balance test that performed by the Hamilton Sundstrand during the full scale development and the F-16 avionics flow balance test that performed by the Lockheed Martin. The avionics flow balance orifice sizing analysis was performed for the A aircraft using a commercial program of the Flowmaster and verified by the flow balance test results performed by Hamilton Sundstrand. The avionics flow balance orifice sizing analysis for the B aircraft was performed with the verified Flowmaster model. The avionics box pressure drop simulation for the B aircraft was performed to define the test facility configuration that best matches the pressure drop characteristics of each avionics box. Also, the initial avionics flow orifices were manufactured based on the analysis results and installed on the avionics flow balance test rig of the B aircraft. The avionics flow balance test was repeated as many times as necessary until the desired avionics flow balance was achieved with the error of ±10%.