[Aerodynamic characteristics of crewman's arms during windblast].
OBJECTIVE
To study the aerodynamic characteristics of crewman's arms with or without protective devices in the status with raised legs or not.


METHODS
The experiments were performed in an FL-24 transonic and supersonic wind tunnel, over Mach number range of 0.4-2.0, with 5 degrees-30 degrees angles of attack, 0 degrees - 90 degrees sideslip angles and Re number of (0.93-3.1) x 10(6). The test model was a 1/5-scale crewman/ejection seat combination. The aerodynamic characteristics of the various sections of crewman's arms were studied and analyzed.


RESULTS
The results showed that 1) The effect of raised leg on the aerodynamic characteristics of the crewman's arms was very evident, and was related to the status of leg raising; 2) The sideslip considerably increased aerodynamic loads on the crewman's arms, in particular when beta=50 degrees the loads was severe in the test; 3) The tested protective devices was valid, the effectiveness of wind deflector in protecting crewman's arms was evident; 4) A formula for calculating aerodynamic force acting on crewman's arms was presented.


CONCLUSIONS
1)The tested protective devices was valid, and the effectiveness of wind deflector in protecting crewman's arms was evident; 2) An aerodynamic basis for the development of crewman windblast protective device was presented; 3)The calculation formula presented is useful in estimating aerodynamic forces of crewman's arms.
Zhang
Yun-ran
YR
Institute of Space Medico-Engineering, Beijing, China.
Wu
Gui-rong
GR
D000401:Aircraft / Q000295:instrumentation; D001132:Arm; D001696:Biomechanical Phenomena; D004867:Equipment Design; D006801:Humans; D007866:Leg; D008297:Male; D008348:Manikins; D008433:Mathematics; D011482:Protective Devices; D014919:Wind