| Automotive engine cooling water pump is a key component in the engine cooling system,the performance of the cooling water pump directly determines whether the engine can run efficiently for a long time,but there are still problems such as low efficiency and high energy consumption.Therefore,this paper takes the 465Q engine cooling water pump as the research object,and develops a new cooling water pump with new hydraulic characteristics through the combination of water pump structure design,CFD numerical simulation and test bench test comparison.The main work of the paper is as follows.1.Automotive engine cooling system and cooling water pump structure form,working principle was briefly introduced;the background and research status of domestic and foreign automotive engine cooling water pump research was summarized by reading a lot of literature.2.The design of the new impeller and volute was completed by adopting the non-equal variable angle spiral as line impeller,semi-open impeller,backward curved vane and 110°wrap angle without changing the installation size of the pump.3.Three dimensional models of prototype water pump and new type water pump were carried out,the fluid domain mesh models were obtained by using ICEM software;new and old pumps were numerically calculated by using Fluent simulation software with SST k-ωturbulence model and SIMPLEC algorithm;compared and analyzed the internal pressure distribution cloud,velocity distribution cloud,impeller velocity vector and cavitation distribution cloud of the old and new pumps under different working conditions,the results show that.1)The internal pressure of the pump increases with the increase of flow rate at rated speed,the impeller inlet and outlet speed increases,and the vortex phenomenon is more obvious in the prototype pump;2)The inlet pressure of the pump decreases with the increase of speed at rated flow rate,the outlet pressure increases,the impeller inlet and outlet speed increases,and the transition of speed in the prototype pump is poor at high speed,resulting in larger shock loss.3)The development pattern of cavitation in the prototype pump and the new pump is more consistent,and the cavitation area gradually diffuses from the initial central axis position to the blade passage.4.External characteristics parameters of the old and new pumps were obtained by using multi-case simulation data and the performance prediction of the new pump was completed.The results show that the new cooling water pump is 0.0375k W lower in power and 5.18%higher in efficiency than the prototype pump under rated working conditions,which completes the performance improvement of the cooling water pump.5.Prototype of the new cooling water pump was developed and the cooling water pump test platform was designed and built independently.The old and new pumps were tested at n=3000r/min,q_v=40L/min,80℃rated working condition respectively by using the pump test platform,the test results show that:1)Under rated working condition,the new cooling water pump has 0.0381k W lower lift power and 4.59%higher efficiency than the prototype pump;2)By comparing the simulation and test data under rated working condition,the maximum relative error is 9.4%;3)Comparing the simulated and tested performance curves under rated working conditions,it is found that the change trend is consistent and the agreement is high,which proves the authenticity and validity of the numerical simulation.6.The new and old pumps were tested at 5 speeds of 1000 r/min,1500 r/min,2000 r/min,2500 r/min and 3000 r/min under 4 fluid temperatures of 75°C,80°C,85°C and 90°C using the pump test platform.The results show that:1)The pump head and efficiency are positively correlated with temperature and the pump power is negatively correlated with temperature at the same speed.2)Under the rated temperature,the head and power of the pump increase with the increase of speed,and the maximum efficiency point gradually shifts to the direction of high flow rate with the increase of speed. |
PDF Full Text Request