There is a consensus in the aerospace field that the development of reusable liquid rockets can effectively reduce the launch expense.The pursuit of a long service life and reutilization highly depends on the bearing ...There is a consensus in the aerospace field that the development of reusable liquid rockets can effectively reduce the launch expense.The pursuit of a long service life and reutilization highly depends on the bearing components.However,the rolling element bearings(REBs)used in the existing rocket turbopumps present obvious and increasing limitations due to their mechanical contacting mode.For REBs,high rotational speed and long service life are two performance indexes that mutually restrict each other.To go beyond the DN value(the product of the bearing bore and rotational speed)limit of REBs,the major space powers have conducted substantial explorations on the use of new types of bearings to replace the REB.This review discusses,first,the crucial role of bearings in rocket turbopumps and the related structural improvements of REBs.Then,with the prospect of application to the next generation of reusable liquid rocket turbopumps,the bearing candidates investigated by major space powers are summarized comprehensively.These promising alternatives to REBs include fluid-film,foil,and magnetic bearings,together with the novel superconducting compound bearings recently proposed by our team.Our more than ten years of relevant research on fluid-film and magnetic bearings are also introduced.This review is meaningful for the development of long-life and highly reliable bearings to be used in future reusable rocket turbopumps.展开更多
In the recovery process of the reusable rocket with vertical take-off and landing,it has to go through the active control process,such as power drop,hover and vertical landing.The key technology lies in the developmen...In the recovery process of the reusable rocket with vertical take-off and landing,it has to go through the active control process,such as power drop,hover and vertical landing.The key technology lies in the development of high-precision vertical recovery control algorithm.Therefore,a vertical take-off and landing reusable launch vehicle prototype is developed to verify the rationality of the flight control algorithm of rocket vertical recovery.The vertical take-off and landing reusable launch vehicle prototype is 0.45 m long,0.45 m wide,0.6 m high,and has 23 kg take-off weight with a maximum thrust of 400 N jet engine as the power plant,through four gas rudders to achieve the aircraft pitch and yaw and roll-on control.The prototype focuses on the verification of the guidance and control algorithm of the vertical recovery algorithm.Therefore,it is equipped with the vector control capability,avionics and measurement system similar to that of the vertical recovery rocket.The prototype can be used for verification of the flight control algorithm.展开更多
基金supported by National Natural Science Foundation of China(61425008,61333004,61273054)Top-Notch Young Talents Program of China,and Aeronautical Foundation of China(2015ZA51013)
基金Supported by National Natural Science Foundation of China(Grant No.51805131)Postdoctoral Research Foundation of China(Grant No.2018M640580)Fundamental Research Funds for the Central Universities(CN)Fundamental Research Funds for the Central Universities of China(Grant No.JZ2018HGBZ0155).
文摘There is a consensus in the aerospace field that the development of reusable liquid rockets can effectively reduce the launch expense.The pursuit of a long service life and reutilization highly depends on the bearing components.However,the rolling element bearings(REBs)used in the existing rocket turbopumps present obvious and increasing limitations due to their mechanical contacting mode.For REBs,high rotational speed and long service life are two performance indexes that mutually restrict each other.To go beyond the DN value(the product of the bearing bore and rotational speed)limit of REBs,the major space powers have conducted substantial explorations on the use of new types of bearings to replace the REB.This review discusses,first,the crucial role of bearings in rocket turbopumps and the related structural improvements of REBs.Then,with the prospect of application to the next generation of reusable liquid rocket turbopumps,the bearing candidates investigated by major space powers are summarized comprehensively.These promising alternatives to REBs include fluid-film,foil,and magnetic bearings,together with the novel superconducting compound bearings recently proposed by our team.Our more than ten years of relevant research on fluid-film and magnetic bearings are also introduced.This review is meaningful for the development of long-life and highly reliable bearings to be used in future reusable rocket turbopumps.
文摘In the recovery process of the reusable rocket with vertical take-off and landing,it has to go through the active control process,such as power drop,hover and vertical landing.The key technology lies in the development of high-precision vertical recovery control algorithm.Therefore,a vertical take-off and landing reusable launch vehicle prototype is developed to verify the rationality of the flight control algorithm of rocket vertical recovery.The vertical take-off and landing reusable launch vehicle prototype is 0.45 m long,0.45 m wide,0.6 m high,and has 23 kg take-off weight with a maximum thrust of 400 N jet engine as the power plant,through four gas rudders to achieve the aircraft pitch and yaw and roll-on control.The prototype focuses on the verification of the guidance and control algorithm of the vertical recovery algorithm.Therefore,it is equipped with the vector control capability,avionics and measurement system similar to that of the vertical recovery rocket.The prototype can be used for verification of the flight control algorithm.
