Facilities

Short Take-Off and Vertical Landing (STOVL) Facility

Experimental Setup for the STOVL Test Facility

The Short Take-Off and Vertical Landing (STOVL) test facility simulates the impinging jet flow field that occurs in STOVL aircraft when in hover mode. A typical setup comprises a nozzle flush mounted in the circular lift plate simulating the undersurface of the aircraft, and a rectangular plate as ground plane. In order to simulate different heights above the ground, the ground plane is mounted on a hydraulic lift and can be moved relative to the lift plate. High-pressure air from the compressor is supplied to the nozzle via settling chamber. A high displacement reciprocating air compressor drives the facility, which is capable of supplying air at a maximum pressure of 2000psia. Large storage tanks provide a total capacity of 10m3 and are capable of driving a typical jet continuously up to 40min. The nozzle is either converging or converging-diverging, resulting in sonic or supersonic flow respectively, when sufficient pressure is applied. An array of microjets, placed appropriately near the nozzle exit is used to control the flowfield in and around impinging jets.

The lift plate, ground plane and other parts of the rig are instrumented using scanivalves, kulite pressure transducers, thermocouples and microphones to measure steady and unsteady pressures, temperature and sound pressure levels respectively. Various flow diagnostic techniques namely shadowgraph/schlieren flow visualization and particle image velocimetry are used to study the flow features of free and impinging jets.

This research is sponsored by the Air Force Office of Scientific Research (AFOSR).