INVESTIGATION OF AXISYMMETRIC DIFFUSERS EXHAUST MANIFOLDS OF TURBOMACHINES WITH SPECIAL INJECTION FLOW

A.Yu. Yudin

The calculation aerodynamic studies results of two axisymmetric axial-radial diffusers with a special injection flow along their outer contours are described. These diffusers exhaust manifolds design for modern steam turbines are typical. The shroud ring radial leakage over rotor blades in computational models of the diffusers is simulated. The following characteristics: the coefficient of the pulse jet injection flow, loss coefficients of the diffuser – the overall, internal and exit velocity are analyzed. The optimum parameters of a special injection are defined. The exit velocity loss on the level of overall losses of the diffuser has the main influence and depends from flow character and circulation zones separating is noted. The comparison of results between the calculated and experimental research is described.

Key words: exhaust manifolds of turbomachines, injection flow, loss coefficients, axisymmetric diffusers, the coefficient of the pulse flow, circulation zone.