Aerodynamic on Reusable Launch Vehicle
RLV (Reusable Launch Vehicle) is expected to become a future space transportation system. We investigate aerodynamic characteristics to improve flight performance, focusing on the fuselage cross sectional shape and morphing concepts and active flow control techniques. Wind tunnel tests and CFD analysis are applied from subsonic to supersonic flight conditions, and flight test using RPV (Remotely Piloted Vehicle) for the approach flight phase.
Aerodynamics focusing on fuselage cross section
To improve the aerodynamic characteristics of RLVs, we propose more efficient aerodynamic configurations of wing-body type RLVs, focusing on the fuselage cross section shapes, than those of conventional RLVs. Combination of the rounded triangle cross section fuselage and the swept wing shows the improvement of lift-to-drag characteristics and maximum lift coefficient.
Lateral blowing for improvement of Aerodynamic characteristics
"Lateral blowing" is one of the active flow control technique to change the flow field around the vehicle by the small amount of gas jet blowing. The results of the wind tunnel test on the wing-body configuration RLV with lateral blowing, which has the blowing perpendicular to the free stream at the wing trailing-edge, showed the significant improvement of the lift characteristics at subsonic flow condition.
Aerodynamic characteristics of TSTO Space Launch Vehicle
TSTO type RLV is one of the most promising launch system for the next generation space transportation. The key issue to realize the TSTO system is the safe separation of the orbiter and the booster at supersonic speed. We are researching on the aerodynamic phenomena of the shock wave/shock wave interaction flow field and the effective vehicle shape to reduce the interaction at supersonic separation, using supersonic wind tunnel tests and CFD analysis.
Flight data measurement using RPV
It is necessary to measure the flight data to estimate the aerodynamic characteristics of real flight conditions, because it is not affected by the wind tunnel wall or the model support equipment which cannot be avoided in the wind tunnel tests. In our laboratory, in-flight data measurement system using RPV (Remotely Piloted Vehicle) have been developed to measure the aerodynamic characteristics data of RLV models. On-board measurement and data transmitter system is installed in the radio-controlled RLV flight test models.
Morphing space transportation system
"Morphing space transportation system" is a new concept for future RLV system. Morphing concept, which changes the vehicle shape to be suited for the flight conditions, is applied to the aerodynamic configuration of space vehicles in order to maintain high aerodynamic performance during all the flight mission. Configuration design is carried out by CFD analysis, and it is verified experimentally in subsonic, transonic and supersonic wind tunnels.
Aerodynamic heating of reentry vehicles
A body travelling at high speeds through the atmosphere experiences aerodynamic heating. We investigate the future thermal protection systems like the opposing jet or the film cooling. Wind tunnel experiments and CFD analysis are applied to elucidate aerodynamic heating phenomena. We also investigate aerocapture technique for Jupiter explore.
Opposing Jet for reduction of aerodynamic heating
The nose part of space transportation vehicle is exposed the most severe aerodynamic heating during the reentry phase. The opposing jet can protect this region by controlling the flow field. Though the ablator or heat resistant tile is used successfully for the contemporary reentry vehicles' thermal protection, these are heavy and poor reusability. The opposing jet is expected as new thermal protection system in the future.
Future propulsion system for aerospace vehicles
We have been studying future propulsion system for next aerospace vehicles.
SCRAM jet engine is air breathing propulsion device used over Mach 5. In combustion stage of this engine, unideal combustion brings performance loss. We are studying how to enhance mixing of fuel and oxidizer by supersonic wind tunnel testing and CFD analysis.
Also we have been studying hybrid rockets which are safer and more cost effective than those of solid and liquid rockets. To realize high fuel regression rate and combustion efficiency, we conduct static firing and flight tests of new combustion method with swirling flow.
SCRAM jet engine
Hybrid rocket engine
Environmental friendly aircraft
"To be environmental friendly" is key problem for next-generation aircrafts. Coping with both eco (low fuel consumption, low noise pollution) and high performance (high capacity of passenger/payload, short runway operation) are challenging tasks when designing small aircraft like an air taxi, which is one solution for on-demand transportation. We are dealing with (1) conceptual design for electrically powered aircraft, (2) wind tunnel investigation for low noise Morphing wing. We are going to integrate these technologies and produce a 6 seats class environmental friendly aircraft in the near future.
Electric powered aircraft
An electric aircraft has superb advantage such as low environmental load, low noise, and low operational cost compared with conventional fossil fuel powered aircrafts. Electric aircraft has also unique characteristic, namely, total mass does not change throughout a flight because of no fuel consumption. To evaluate its feasibility, we are studying conceptual design method. In addition, we are conducting flight test of radio controlled scale models to validate our design processes.
Low noise morphing flap
We are studying mechanisms of emission and propagation of noise around a wing with making full use of Low-noise low-speed wind tunnel in our department. Morphing flap is promising device to realize both high lift and low noise at takeoff or landing. We demonstrated significant noise reduction by phased array microphone system.
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Variable porosity distribution wing for Gust Load Alleviation(GLA)
We are studying on variable porosity distribution wing for aircraft gust load allviation(GLA). Internal flow through the porous surfaces and the vabiable vanes generated by the pressure difference between both sides of the wing.
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As an application of Morphing concept that transforms airframe smoothly during flight, we are studying Morphing Wing that transforms wing section smoothly. In addition, we developed Morphing Circulation Control Wing which produces high lift by the Coanda effect, and are analyzing by experiments and CFD.
QSAT-EOS(Kyushu Satellite for Earth Observation System Demonstration) is a 50kg class satellite developing by universities and companies within Kyushu district. Preparation of ground station and construction of data analysis system for the operation after its launch have been progressing.
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