EFFECT OF ROTOR'S ASPECT RATIO ON ENTROPY GENERATION IN A ROTOR-CASING ASSEMBLY

摘要

Computational Fluid Dynamics (CFD) is used to simulate the flow filed in a rotor-casing assembly for different elliptic rotor aspect ratios and inlet flow velocities. The flow was simulated with the rotor fixed at its extreme positions, i.e. vertical and horizontal arrangement. The flow field results were used to ascertain the changes in the efficiency of a rotor-casing assembly. This included: inlet pressure, maximum velocity, and maximum turbulence values. A more fundamental quantity, integrated entropy generation was also calculated. Entropy generation is based on the second law of thermodynamic and accounts for all types of irreversibilties within the assembly. Of the different traditional quantities calculated, only the inlet pressure results were inline with the entropy generation results.