Development of a 2D solid state LDA for velocity measurements in turbulent bearing flow

A two-dimensional solid state LDA system was developed for the measurement of turbulent flow in a test journal bearing. Visible laser diode and avalanche photodiode were employed in the design of the LDA optics and optical frequency shifts were used to separate signals and remove directional ambiguity. Special techniques were tested to minimize the influence of the diffused light from the shaft surface and make valid measurements near the walls. Two-component measurements were made in a journal bearing with a minimum gap of 0.49 mm and velocity profiles under different Reynolds numbers were obtained.