Modelling of the tip clearance losses in axial flow machinesModelling of the tip clearance losses in axial flow machines Πλήρης Δημοσίευση σε Συνέδριο Conference Full Paper 2015-11-041996enThe possibility of predicting the total pressure loss radial distribution, due to the tip clearance presence, is examined in this paper. Models advanced for the diffusion of a line vortex are used for the simulation of the leakage vortex induced velocity and pressure fields, with sufficient success. The leakage vortex strength seems to control directly only a small part of the total pressure loss distribution, the one connected with the pressure deficit and the rotating flow. The remaining profiles result as functions of a free parameter — the constant of integration — and an assumption is needed to close the problem. The widely proposed observation for lost secondary jet kinetic energy is considered as a method of predicting the total amount of tip clearance loss in successive planes inside and downstream the blade passage. A calculation procedure for predicting the tip clearance effects in the flow field inside and downstream the tip clearance, has been developed. The method, being compatible with a meridional flow calculation procedure, accounts for the calculation of the peripherally mean deficit profiles of the various flow quantities. The predictive capability of the calculation procedure is established in a wide range of test cases, including axial flow compressor cascades, isolated rotors and multi-row machines. The radial variation of tip clearance pressure loss is calculated with sufficient accuracy for engineering purposes.http://creativecommons.org/licenses/by/4.0/ASME 1996 International Gas Turbine and Aeroengine Congress and Exhibition Nikolos Ioannis Νικολος Ιωαννης K. D. Papailiou D. I. Douvikas American Society of Mechanical Engineers