| With the rapid development high speed railway system in our country, it is an important subject to provide the high resistance, high efficiency as well as low noise fan with the high speed railway in front of the fan designers.In the past, non-dimensional design parameters similarity method which used to ordinary civil fan mostly was used to the design in the rail fan research, often frustrated. The test results could not reach the fan design specifications, which lead to repeated design.this is not only an economic loss, and will miss the opportunity in the market competition. So it is the requirement of social development to establish applying to rail fan design system. In this paper, combined with electric locomotive traction cooling fan design, systematicly studied one-dimentional, two-dimentional and three-dimentional design theory. Meanwhile, the performance experiment, noise performance, speed experiment and vibration experiment have been done. The main findings of this paper are as follows:1. This article discussed fan one-dimentional design principle deeply and analyzed the fan loss model and loss calculation formula. The correlation between the fan internal efficiency and total pressure efficiency was given (regardless of duct’s abrupt area increasement and leakage loss). An important theoretical basis was provided for three-dimensional numerical calculation of the correction. The calculation results showed that duct’s abrupt area and stator’s reverse flow zone would incur significant and noticeable losses, which cannot be underestimated in fan design.2. In the two-dimentional design, multi-section’s blade design which based on the results of S2calculation has been done. And the intensity of the final model was checked by the FEM ANSYS software. The distribution pattern and strength check results of the major flow’s design parameter were provided.3. In order to verify the accuracy of fan CFD numerical calculation, a single stage fan was calculated, and the calculation result was satisfied. In the design point, the mass flow rate and pressure of fan were higher than the design point calculation value by2.5%. In the oblique flow three-dimensional design, simplified CFD numerical calculation could’t simulate completely the true fan flow state, The results showed that major design parameter was enlarged in order to fulfill the request of the fan’s design and the static pressure is4500Pa. based on this, completed the blade shape and three-dimensional CFD numerical calculation. Oblique flow fan performance test met the design requirements.Performance curve which reached by the experiment was compared to the CFD results, the result was that two curve basicly coincided near the blocked flow. The lower the flow was, the higher the pressure was, and the greater the deviation. The main reason was that fan backflow loss and the sudden enlargement loss were not considered in CFD calculation. It could be completed and developed in the furture.4. In this paper,oblique flow fan optimization design was completed by the application of building fan design system.In the design speed, the design objective were:revolution speed was2950r/min, mass flow of the fan was5.5m3/s,static pressure was above3600Pa,total efficiency was above60%and the fan noise was not more than110dB(A). Experiment results were:at the design speed, the mass flow was5.56m3/s, static pressure was3817Pa, total efficiency was above74.96%and the fan noise was101.52dB(A), and fan worked smoothly, small vibration. Under the condition of10%overspeed experiment the fan blade had no obvious deformation. All the experimental results showed that the fan has met the request of the deisgn fully, and its efficiency has reached the domestic advanced level of rail fan. |
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