Flow characteristics of viscous oil in rotor cavity of cam pump
1.School of Energy and Power Engineering, Lanzhou University of Technology, Lanzhou, Gansu 730050, China; 2. Wenzhou Pump and Valve Engineering Research Institute, Lanzhou University of Technology, Wenzhou, Zhejiang 325100, China; 3. School of Mechanical Engineering, Chongqing University of Technology, Chongqing 400054, China
Abstract： To investigate the effects of viscosity, differential pressure and speed on the performance of cam pump, and analyze the change law of flow rate and excitation force, under different viscosity, differential pressure and speed, the three-dimensional transient numerical calculation of the flow field of cam pump was carried out and verified by experiments. The results show that with the increasing of viscosity from 1.8×10-5 m2·s-1to 2.2×10-4 m2·s-1, the outlet flow rate is increased from 16.856 m3·h-1 to 20.736 m3·h-1, and the outlet flow pulsation becomes stable with increased volume efficiency and widened high-speed zone of inlet and outlet. When the differential pressure is increased from 0.1 MPa to 0.6 MPa, the outlet flow rate and volume efficiency are decreased, while the outlet flow pulsation is basically consistent. The maximum absolute value of the force in x direction is increased from 514.04 N to 1 893.37 N, and the maximum value of the force in y direction is increased from 1 709.17 N to 8 855.57 N. When the speed is increased from 100 r·min-1 to 300 r·min-1, the flow rate and volume efficiency at the outlet are increased, and the average pressure at the outlet is increased from 400.552 kPa to 405.117 kPa, while the outlet flow pulsation and pressure pulsation are increased. The maximum absolute value of the force in x direction is increased from 1 211.17 N to 1 513.11 N, and the maximum value of the force in y direction is increased from 5 810.77 N to 6 276.51 N.
MIMMI G, PENNACCHI P. Dynamic effects of pressure loads in three screw pump rotors[J]. Journal of Mechanical Design, Transactions of the ASME, 1998, 120(4): 589-592.
［2］
MIMMI G, PENNACCHI P. Compression load dynamics in a special helical blower: a modeling improvement[J]. Journal of Mechanical Design, Transactions of the ASME, 2001, 123(3): 402-407.
［3］
LI Y B, GUO D S, LI X B. Mitigation of radial exciting force of rotary lobe pump by gradually varied gap[J]. Engineering Applications of Computational Fluid Mechanics, 2018, 12: 711-723.
YANG C L, TANG C, SHEN X G. Calculation and design for geometric parameter of inner joggling cycloidcycloid rotor pump[J]. Mechanical Research & Application, 2019, 32(3): 92-94，100. (in Chinese)
LI H Y, ZHAO Y G, HU L, et al. The improvement study on involute profile type rotor profile in roots vacuum pump[J]. Machine Tool & Hydraulics, 2011, 39(22): 37-39. (in Chinese)
LI Y L, LIU P, CHEN Y, et al. Study on general model of flow ripple coefficient for rotor pump[J]. Fluid Machinery, 2020, 48(8): 42-46. (in Chinese)
［7］
WU Y R, TRAN V T. Generation method for a novel roots rotor profile to improve performance of dry multistage vacuum pumps[J]. Mechanism and Machine Theory, 2018, 128: 475-491.
［8］
ARJENEH M, KOVACEVIC A, RANE S, et al. Numerical and experimental investigation of pressure losses at suction of a twin screw compressor[C]//IOP Conference Series: Materials Science and Engineering. London,UK: IOP Publishing Ltd, 2015: 1-10.
［9］
HUANG Z F, LIU Z X. Numerical study of a positive displacement blower[J]. Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science, 2009, 223: 2309-2316.
LI Y B, ZHANG X Z, GUO D S, et al. Numerical analysis and verification of flow characteristics of rotorcavity of spiral rotary lobe pump[J]. Transactions of the Chinese Society of Agricultural Engineering, 2018, 34(10): 62-67. (in Chinese)
LI Y B, LI R N, JIA K, et al. Dynamic mesh simulation and analysis for inner flow field of cam pump[J]. Journal of Jiangsu University(Natural Science Edition), 2014,35(5): 518-524. (in Chinese)
WU M L, CHEN W B, YUE X Q, et al. Analysis on flow pulsation of the doublesided groove′s camdriven pump[J]. Journal of Machine Design, 2019, 36(12): 84-89. (in Chinese)
SHEN H, SANG X H, LI Y B, et al. Rotor design of lobe pump and numerical simulation of transient performance of its interior flow field[J]. Journal of Lanzhou University of Technology, 2014, 40(4): 40-44. (in Chinese)
CHEN Z B, ZOU Y Z, JIANG Z, et al. Numerical simulation of the effect of the gap between rotor and pump on the performance of the rotor pump[J]. Noise and Vibration Control, 2017, 37(2): 62-66. (in Chinese)
LIAN J D, PAN G J, ZHU Z F. Numerical analysis and verification of pressure characteristics of elastomeric rotor pumps[J]. Journal of Drainage and Irrigation Machinery Engineering, 2020, 38(10): 985-990，1056. (in Chinese)
LI Y, JIANG X J, QIAN H H. Numerical investigation of viscosity impact on rotary lobe pump performance[J]. Journal of Drainage and Irrigation Machinery Engineering, 2014, 32(8):669-673. (in Chinese)
