Engineering topics

Beatty, P. A.

Publications and source records attributed to Beatty, P. A..

3 records

NASA NTRS1994

Analyzing Seals With Two-Phase Flows

SEAL computer program analyzes steady-state performance of face seal with two-phase leakage flow. Calculates general trends of performance under both low- and high-leakage conditions and, by extrapolation, behavior in intermediate region. Parameters investigated include subcooling, coning of seal faces, speeds of rotation, conductivities of seal materials, and widths of seal faces. Program incorporates idealized mathematical models, and based on finite-difference approach. Written in FORTRAN 77.

Lau, S.↗

NASA NTRS1990

A simplified model for two phase face seal design

A simplified quasi-isothermal low-leakage laminar model for analyzing the stiffness and the stability characteristics of two-phase face seals with real fluids is developed. Sample calculations with this model for low-leakage operations are compared with calculations for high-leakage operations, performed using the adiabatic turbulent model of Beatty and Hughes (1987). It was found that the seal characteristics predicted using the two extreme models tend to overlap with each other, indicating that the simplified laminar model may be a useful tool for seal design. The effect of coning was investigated using the simplified model. The results show that, for the same balance, a coned seal has a higher leakage rate than a parallel face seal.

Lau, S. Y.↗

NASA NTRS1986

Turbulent two-phase flow in annular seals

Steady, turbulent two-phase fluid flow in a rotating annular seal with no eccentricity is analyzed. The fluid is assumed to be a homogeneous mixture of liquid and vapor in thermodynamic equilibrum. Further, the flow is assumed to be adiabatic, but the effects due to heat generation by viscous dissipation are accounted for fully. Solution of the model governing differential equations is accomplished by use of a fourth-order Runge-Kutta numerical integration scheme. The calculation of mass leakage rates under choked and unchoked conditions are discussed and the phenomenon of all-liquid choked flow is explained. Several numerical examples are presented supposing cyrogenic oxygen as the sealed fluid.

Beatty, P. A.↗