Dissertation > Excellent graduate degree dissertation topics show

Numerical Study of the Effect with Straight and Bowed Stator in Different Axial Gaps

Author: WanJiLin
Tutor: ChenFu
School: Harbin Institute of Technology
Course: Power Machinery and Engineering
Keywords: Compressor Positive dihedral blade Axial gap Interference between blade rows Aerodynamic performance
CLC: TH45
Type: Master's thesis
Year: 2008
Downloads: 57
Quote: 0
Read: Download Dissertation

Abstract


The development of higher efficiency and larger thrust-weight ratio of aeroengine has put a further demand on the aerodynamic performance of compressor component. The method improving the compressor’s aeroperformance by changes of geometrical shape among flow passage will be promising. Based on this understanding, the method of 3-D numerical simulation is adopted to investigate the two stages of a low speed compressor in the dissertation, and it was by means of changing the type of stators(straight blade and positive dihedral blade) and varying the axial gap between rotor and stator to realize the changes of geometrical shape among flow passage through the research.Firstly,the performance of the two original axial gap compressors which used straight stator and the positive dihedral stator was investigated. The result shows that the shaft work of the compressor with positive dihedral stator is less than the compressor with straight stator, and the reducing of the shaft work is a positive element for the efficiency rising, and it also proved that positive dihedral stator weakened the potential flow interference. The efficiency of the compressor with positive dihedral stator is all higher than that with straight stator at all working conditions in different degree, and the positive dihedral stator also increases the stall margin of the compressor. However, comparing to the straight stator the positive dihedral stator reduced the turning angel of the air flow and the mass flow rate of the compressor. The positive dihedral stator changed the static pressure distribution on the surface of blade, and it establishs the C-type pressure distribution on the suction surface, which means that the static pressure near end wall is higher than that far from the end wall in radial direction. Thus, the boundary layer fluid would move to middle region of blade under the psid, which could restrain the boundary layer fluid’s accumulation on the blade surface near end wall effectively.This dissertation establishes two methods which also be investigated with straight stator and positive dihedral stator to reduce the axial gap based on original axial gap. The result shows that reducing the axial gap increased the torque, and that proved that small axial gap strengthen the potential flow interference. Smaller axial gap is helpful to improve the aerodynamic performance of compressor. however, it will worsen the aerodynamic performance of a compressor if the axial gap is too small, such as it reduce a compressor’s stall margin. This also proved that there is a certain axial gap with which a compressor can achieve optimal aerodynamic performance. Further, the performance of the compresspor works at the near stall condition is the most sensitive to axial gap varying, the maximum flow rate condition is the least one, and the design condition take the middle place. Comparing to the compressor with positive dihedral stator, the compressor with straight stator is sensitive to axial gap varying.

Related Dissertations

  1. Development of the Platform for Compressor Optimization Design and Aerodynamic Optimization Design in the Transonic Compressor,TH45
  2. Numerical Investigation of Effects of Boundary Layer Suction on the Performance of Diffusion Cascade,TH453
  3. Design and Application of Centrifugal Compressor Monitoring System,TP277
  4. Research of A Practical Nanosecond High-voltage Pulse Power Source,TM46
  5. Research on Reverse Rotation During the Multi-Stage Centrifugal Compressor Failure Shutdown Process,TH452
  6. Large air conditioning unit noise isolation technology development and implementation,TB535.1
  7. Vane air compressor performance analysis of key components and research,TH455
  8. Single screw compressor screw meshing pair Manufacturing Technology,TH45
  9. Inverter refrigerator system dynamics and control strategy,TB657.4
  10. Screw Air Compressor Testing System Research and Implementation,TH45
  11. The Design and Application of Wind Turbine Airfoil Considering the Aerodyamic Noise,TK83
  12. Study on Measurement Technology and Expression of Twin-screw Compressor Rotor Profile,TH45
  13. A Study on the Portable Dynamic Signal Acquistion and Analysis System of Reciprocating Compressor,TH45
  14. Research on Prediction Model of New Rotary Vane Compressor,TH45
  15. Study on the Performance of Cascade and Stage and of Helium Compressor with Heavy Stage Load,TH45
  16. Research and Implementation of the new inverter air conditioner electrical system,TM925.12
  17. Design of Motor Protection of Air Compressor Used in Coal Mine Based on ARM,TM307
  18. The Numerical Simulation of Aerodynamic Performance for New-style Chain-drive Wind Machine,TK83
  19. Flow Field Numerical Simulation of Windmill Blade Based on Magnus Effect,TK83
  20. Key Technology Research of Direct-Expansion Solar Assisted Heat Pump’s Adjustment and Control,TK513

CLC: > Industrial Technology > Machinery and Instrument Industry > Gas compression and transportation machinery > Compressors, compressor
© 2012 www.DissertationTopic.Net  Mobile