METHODOLOGY FOR COMPARATIVE ANALYSIS AND NUMERICAL EVALUATION OF THE SURFACE TEXTURE OF CENTRIFUGAL PUMP IMPELLER BLADES

Abstract

Increasing the hydraulic efficiency of centrifugal pumps remains a priority task for energy conservation. One promising passive method of controlling near-wall flow is the artificial texturing of blade surfaces. In this work, two competing families of textures—localized dimples and longitudinal grooves—are comparatively analyzed on the basis of four independent studies concerning modified surfaces and flow in the flow passage of a rotating turbomachine. It is shown that dimples promote vortex formation and turbulent transport and generally increase friction, whereas longitudinal grooves reorganize the flow core within a certain range of parameters and reduce shear stress. The main contradiction is that the two texture families have been studied according to incompatible target functions (resistance to heat transfer) and on stationary objects, whereas the function of an impeller requires minimizing hydraulic losses in a rotating curved channel. A unified computational methodology for the comparative assessment of blade textures is proposed, combining a TEF-type compromise metric, a friction modification coefficient, and a workflow for CFD modeling of an impeller. The scientific gap, hypotheses for transferring the mechanisms, and the computational experimental plan are described.