Research on Clearance Flow of Microscopic Surface Influence

Using Weierstrass-Mandelbrot (W-M) function, characterization is done on the microscopic surface contours, structure function and scale consistent with a power-law relationship. The WeierstrassMandelbrot function is introduced to characterize the surface spool’s microscopic surface. It can be certificated by the structure function and scale consistent with Power-Law. With CFD method, numerical simulation was made on the rough surface. The two-dimensional cross-section model of the valve-gap is established, and it is simulated by FLUENT and compared with the ideal smooth surface. Results show that rough valve clearance formed by the pressure drop is significantly larger than that of the desired glossy surface. In the end, this article shows that the roughness, good sealing and pressure maintaining requirement can be satisfied by increasing the annular groove.