These factors can not be entirely reproduced in a test chamber, where only the flow submerging the drone can be analyzed. The comparison between CFD and test data is made at the inlet of the engine ventilation scoops where the total pressure rakes are compared. Very good agreement between the free jet and free field simulations and test data is achieved along the body of the drone. However, the free jet and free field simulations diverge at 1.7 m from the nozzle outlet, where the fluid region representative of fight is a cylinder with a radius of 0.5 m for an initial nozzle exit radius of 0.9 m. Thus, for the part of the drone outside the cylinder, the ground test is not representative of flight conditions.
Static pressure contours on the drone surface.
Total pressure at the scoop inlet of the jet engine. The objective of these studies is to gather data that enable them to adapt the test chamber for ramjet tests. Simulations are run for steady, compressible, viscous flow using the k-epsilon turbulence model. There is very good agreement between experimental and computed data. The center at Saclay continues to use CFD in innovative ways to expand their analysis capabilities and complement experimental testing.