【摘 要】
：
To address deeper understandings about the aero-thermal performance of an integrating infrared suppressor under more realistic situations,a numerical investigation is motivated in the cur-rent study,concerning the effects of forward-flight speed on exhaus
【机 构】
：
Key Laboratory of Thermal Management and Energy Utilization of Aircraft of Ministry of Industry and
论文部分内容阅读
To address deeper understandings about the aero-thermal performance of an integrating infrared suppressor under more realistic situations,a numerical investigation is motivated in the cur-rent study,concerning the effects of forward-flight speed on exhaust plume flow and infrared radi-ation of the Infrared Suppressor-integrating (IRS-integrating) helicopter,wherein the forward-flight speed is changed from 0 m/s (hover state) to 100 m/s,while both the engine exhaust parameters and the main-rotor operation parameters remains unchanged during different forward-flight velocities.The results show that the interaction between forward-flight flow and downwash flow alters the exhaust plume development and the internal flow inside the IRS-integrating rear fuselage more com-plicatedly,tightly dependent on the forward-flight speed.Of particular concern is the situation where the forward-flight flow has nearly the same level as the downwash flow,the hot mixing flow could possibly interacts with the helicopter rear fuselage to play a local heating effect.With the increase of forward-flight speed,the ejection coefficient is generally increased and the average exhaust tem-perature of mixing flow is decreased,leading to a reduction of the infrared radiation intensity of exhaust plume in 3-5 μm band.However,the influence of forward-flight speed on the overall infrared radiation intensity of IRS-integrating helicopter is conjectured not monotonous due to the compli-cated interaction between forward-flight flow and downwash flow.Under high-speed forward-flight states,the overall infrared radiation intensity of the IRS-integrating helicopter in 3-5 μm band is reduced with the increase of forward-flight speed.With respect to 35 μm band,the forward-flight speed has little effect on the infrared radiation in 8-14 μm band.
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