| The fuel centrifugal pump is the core component in the fuel system of the rocket propulsion engine.With the rapid development of China’s manned spaceflight and military equipment,the research on the centrifugal pump is mainly focused on higher speed and smaller specific revolution due to the endless pursuit of its small size,light weight and high performance,which also results in such issues as pump structure,hydraulics,mechanics,heat transfer.This research is mainly focuses on the above issues.Through the theoretical analysis of turbo machinery,CFD numerical simulation and experimental research,an integrated centrifugal pump with high speed and small specific speed is developed.Firstly,according to the working mode,performance requirements and other characteristics of a certain type of rocket engine fuel centrifugal pump,referring to the design of existing centrifugal pumps,the relevant advantages and disadvantages were summarized,then the pumpdrive motor integration design principle is adopted.The spiral groove structure of motor rotor is proposed for the first time to improve the comprehensive performance of the pump.Secondly,the diffuser the impeller,volute and other main parts are optimized.The impeller and volute of the integrated pump are parametrically designed by using the turbo-machinery design software CFturbo.The part drawing,assembly drawing and full flow fluid domain model of the integrated pump are constructed with the software of Solid Works.On the basis of the established fluid domain model of the whole flow field,the Ansys-Fluent software is used to conduct hydraulic numerical simulation under steady conditions.The transient process of the pump is simulated by establishing turbulence model,establishing grid type and applying three basic equations of fluid mechanics.After numerical calculation,the static pressure,flow velocity,streamline and turbulent kinetic energy diagram of the whole flow field of the integrated pump under different working conditions are obtained,and the external characteristics of the integrated pump are verified to obtain its water-lift and hydraulic efficiency.Under transient conditions,the pressure pulsation of the integrated pump under different flow conditions is analyzed,and the pressure pulsations of the average pressure in both time domain and frequency domain are studied.The cavitation allowance and internal high static pressure distribution of the integrated pump are also analyzed to provide a basis for modifying the structural parameters of the centrifugal pump impeller and volute.Because of the spiral grooves creatively provided to the motor rotor,the fluid medium participates in the working cycle,the fluid structure coupling and modal analysis methods are used to deeply discuss the characteristics of the integrated pump.At the same time,in view of the extreme environment in which the integrated pump works,the temperature field of the drive-motor under different flow and speed conditions is analyzed.The results show that the axial force is effectively reduced and the temperature rise is restrained obviously as well.Based on the simulation results,the local parameters of the original integrated pump are modified,the integrated pump part drawings are reconstructed,and five prototypes are processed for testing.Firstly,the structure and measurement and control system of the integrated pump testbed at different stages are studied.Then the integrated pump hydraulic characteristics test-bed is selected,assembled and built.The integrated pump is tested with water and RP-3 medium under different voltages,flows and inlet pressures.It shows that the test results are consistent with the numerical simulation results of hydraulic characteristics,and all performance indicators satisfy the requirements of the overall operating performance.136 figures,43 tables and 135 references included in the paper... |
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