Accession Number : ADA190677

Title :   Cavitation Inception in Rectangular Two-Dimensional Slots.

Descriptive Note : Master's thesis,

Corporate Author : PENNSYLVANIA STATE UNIV UNIVERSITY PARK APPLIED RESEARCH LAB

Personal Author(s) : Blair, W G ; Cimbala, J M

PDF Url : ADA190677

Report Date : Dec 1987

Pagination or Media Count : 140

Abstract : The two dimensional fluid mechanics of flow over a rectangular slot along a flat wall were studied in air. A thick (greater than slot width) turbulent boundary layer was established at the slot entrance location. The flow field within and at the slot entrance was studied as the slot geometry was varied for depth-to-width ratios (aspects ratios) ranging from 0.5 to 3.0. Flow visualization inside the slot describes the internal flow field of the slot and reveals the highly unsteady nature of the vortex-like structure(s) that develop. Flow visualization of the slot region entrance shows that mass. Flow visualization as well as direct pressure measurements inside the slot document vortex location as a function of aspect ratio. The minimum pressure in the slot, found at the primary vortex center, is also documented as a function of aspect ratio. The measured pressure coefficients inside the slot are an order of magnitude lower than those of which cavitation has been observed in previous water tunnel experiments. These measurements therefore lead to question the interpretation of the previous water tunnel slot cavitation experiments. Specifically, it is likely that the previously reported cavitation was partially gaseous rather than purely vaporous cavitation, as had been assumed.

Descriptors :   *CAVITATION, *SLOTS, *TURBULENT BOUNDARY LAYER, *VORTICES, *BOUNDARY LAYER FLOW, ASPECT RATIO, COEFFICIENTS, FLOW FIELDS, FLOW VISUALIZATION, GEOMETRIC FORMS, INTERNAL, PRESSURE, PRESSURE MEASUREMENT, RECTANGULAR BODIES, TWO DIMENSIONAL, WALLS, WATER, WATER TUNNELS, WIDTH, TWO DIMENSIONAL FLOW

Subject Categories : Fluid Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE