Ramjet Engine Testing and Simulation Techniques

Simulation of flow conditions within the operating regime of ramjet engines requires unique ground test capabilities. The blowdown facility is an economical method of meeting the high air mass flow and pressure ratio requirements. Vitiated air heaters provide a flexible and cost-effective method of simulating trajectory temperature variation. Adequate simulation of the inlet flow conditions in freejet tests plays an important role in engine development. Ramjet engine ground test requirements are discussed. Methods of simulating the applicable parameters in direct-connect and freejet tests are reviewed. Techniques and devices that have proved beneficial in meeting aerodynamic simulation requirements are described.