Flow Field Properties Around Flight Deck Of Destroyer And Investigations On Flow Control Methods

Shipboard helicopter landing operations on the flight deck of a small warship is one of the mostdifficult flying skills for pilots to master. Outstanding safety problems have seriously affected theexpanded sea-air combat missions. During the voyage, tilt, swing, restricted space, and unsteady flowfield are main factors that affect safe landing. Since tilt, swing, and restricted space are factors thatinevitable to change, improving the flow field can be effective method to ameliorate the safety ofhelicopter landing on the deck. Flow control technology is the cutting-edge technology of fluiddynamics, and has been widely used in aircraft pneumatic control. This paper apply flow controltechnology to the flight deck of a destroyer model in order to improve the flow field. It can beeffectively to improve the condition of the flow field near the deck, expand the envelope for flightoperations, and ameliorate the safety for helicopter to land on the deck.This paper is mainly based on wind tunnel experiment and uses a1:100scale model of destroyerto explore the problem. Flow control technology is used to improve flow characteristics near the deck;via warships-helicopter coupling experiment to test and verify the effect of flow control.Firstly, flow visualization is used for the qualitative study of warships tail flow field. Then useseven-hole probe flow field test system and particle image velocimetry system (PIV) to measure thespatial flow structure of the flight deck quantitatively. On this basis, the dynamic pressuremeasurement technology, combined with PIV transient results, is applied to figure out the dynamiccharacteristics of the flow field deck. Two experiment schemes are designed to simulate the process ofhelicopter landing, and the interference between wake flow and helicopter rotor is measured by thePIV and balance. Figure out several characteristic structures which impact on the helicopter landingseriously and targeted several flow control scheme designed to control. Use the seven-hole probetesting technology to measure the results of controlled flow field, and find out effective controlmethods after analysis and comparison. Finally, the balance and PIV technology are used to measurethe impact of control methods on the helicopter rotor flow and aerodynamic directly. The optimalcontrol method selected in this paper can cause a reduction in the sudden increased forward suction of17.9%while the helicopter entering into the aft flight deck.