Simulation of Gas Transportation in Radial Shaft Seal With Model Surfaces

This paper describes an analytical study on gas transportation in radial shaft seal. A model is constructed in which seal surfaces with sinusoidal roughness, lubricant flow at the seal lip with gaseous cavity, dissolution of gas into and release of gas from the lubricant across double boundary films at gas-liquid interfaces, and convection of dissolved gas in the lubricant flow are considered. Polyalphaolefin as a lubricant, and helium, argon and carbon dioxide are assumed. The results demonstrate that the axial flow induced by surface roughness carries the gas, and that the gas flow through the lubricant film is proportional to the gas solubility coefficient, and the circumferential speed of the shaft, which agrees with the experimental finding for actual seals. The dependence of the gas flow on the axial flow of the oil and that on the boundary films are discussed.

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Introduction to Engineering Fluid Mechanics

10.1093/oso/9780198719878.001.0001 ◽

2018 ◽

Author(s):

Marcel Escudier

Keyword(s):

Fluid Mechanics ◽

Dimensional Analysis ◽

Gas Flow ◽

Stokes Equations ◽

Reaction Force ◽

Axial Flow ◽

Hydraulic Turbine ◽

Navier Stokes ◽

Pipe Bend ◽

Flow Through

Turbojet and turbofan engines, rocket motors, road vehicles, aircraft, pumps, compressors, and turbines are examples of machines which require a knowledge of fluid mechanics for their design. The aim of this undergraduate-level textbook is to introduce the physical concepts and conservation laws which underlie the subject of fluid mechanics and show how they can be applied to practical engineering problems. The first ten chapters are concerned with fluid properties, dimensional analysis, the pressure variation in a fluid at rest (hydrostatics) and the associated forces on submerged surfaces, the relationship between pressure and velocity in the absence of viscosity, and fluid flow through straight pipes and bends. The examples used to illustrate the application of this introductory material include the calculation of rocket-motor thrust, jet-engine thrust, the reaction force required to restrain a pipe bend or junction, and the power generated by a hydraulic turbine. Compressible-gas flow is then dealt with, including flow through nozzles, normal and oblique shock waves, centred expansion fans, pipe flow with friction or wall heating, and flow through axial-flow turbomachinery blading. The fundamental Navier-Stokes equations are then derived from first principles, and examples given of their application to pipe and channel flows and to boundary layers. The final chapter is concerned with turbulent flow. Throughout the book the importance of dimensions and dimensional analysis is stressed. A historical perspective is provided by an appendix which gives brief biographical information about those engineers and scientists whose names are associated with key developments in fluid mechanics.

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Two-Dimensional Inflow Conditions for a Supersonic Compressor With Curved Blades

Journal of Applied Mechanics ◽

10.1115/1.4011491 ◽

1957 ◽

Vol 24 (2) ◽

pp. 165-169

Author(s):

Philip Levine

Keyword(s):

Flow Field ◽

Analytical Study ◽

Flow Model ◽

Axial Flow ◽

Entrance Region ◽

Suction Surface ◽

Isentropic Flow ◽

Blade Row ◽

Flow Through ◽

Inflow Conditions

Abstract Results are presented on an analytical study of the flow field existing upstream of a blade row, where the axial flow is subsonic and the relative flow is supersonic. The flow model used as a basis for the calculations assumes isentropic flow, and considers the case where the suction surface is a circular arc in the entrance region. The results clearly show the unique dependence of the flow through a blade row upon the geometry of the entrance region. Using the results, the complete flow field in the entrance region and upstream of the blade row can be constructed easily.

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INVESTIGATION OF THE TIME OF GAS FLOW THROUGH A HOLE IN LONG PIPELINES UNDER HIGH PRESSURE

Transactions of Academenergo ◽

10.34129/2070-4755-2020-58-1-30-43 ◽

2020 ◽

Vol 58 (1) ◽

pp. 30-43

Author(s):

N.D. Yakimov ◽

◽

A.I. Khafizova ◽

N.D. Chichirova ◽

O.S. Dmitrieva ◽

...

Keyword(s):

High Pressure ◽

Gas Flow ◽

Flow Through

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Free area for gas flow through sieve plates with a bubbled bed

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19753315 ◽

1975 ◽

Vol 40 (11) ◽

pp. 3315-3318 ◽

Cited By ~ 1

Author(s):

M. Rylek ◽

F. Kaštánek ◽

L. Nývlt ◽

J. Kratochvíl

Keyword(s):

Gas Flow ◽

Flow Through ◽

Sieve Plates ◽

Free Area

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Flow through axial-flow-turbomachinery blading

10.1093/oso/9780198719878.003.0014 ◽

2018 ◽

Author(s):

Marcel Escudier

Keyword(s):

Flow Velocity ◽

Compressible Flow ◽

Dimensional Analysis ◽

Incompressible Flow ◽

Compressible Fluid ◽

Axial Flow ◽

Linear Cascade ◽

Dimensional Parameters ◽

Flow Through

This chapter is concerned primarily with the flow of a compressible fluid through stationary and moving blading, for the most part using the analysis introduced in Chapter 11. The principles of dimensional analysis are applied to determine the appropriate non-dimensional parameters to characterise the performance of a turbomachine. The analysis of incompressible flow through a linear cascade of aerofoil-like blades is followed by the analysis of compressible flow. Velocity triangles for flow relative to blades, and Euler’s turbomachinery equation, are introduced to analyse flow through a rotor. The concepts introduced are applied to the analysis of an axial-turbomachine stage comprising a stator and a rotor, which applies to either a compressor or a turbine.

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A Study on Liquid Leak Rates in Packing Seals

Applied Sciences ◽

10.3390/app11041936 ◽

2021 ◽

Vol 11 (4) ◽

pp. 1936

Author(s):

Abdel-Hakim Bouzid

Keyword(s):

Environmental Protection ◽

Liquid Flow ◽

Environmental Protection Agency ◽

Gas Flow ◽

Outer Boundary ◽

Health And Safety ◽

Toxic Substances ◽

Packing Materials ◽

Thickness Change ◽

Flow Through

The accurate prediction of liquid leak rates in packing seals is an important step in the design of stuffing boxes, in order to comply with environmental protection laws and health and safety regulations regarding the release of toxic substances or fugitive emissions, such as those implemented by the Environmental Protection Agency (EPA) and the Technische Anleitung zur Reinhaltung der Luft (TA Luft). Most recent studies conducted on seals have concentrated on the prediction of gas flow, with little to no effort put toward predicting liquid flow. As a result, there is a need to simulate liquid flow through sealing materials in order to predict leakage into the outer boundary. Modelling of liquid flow through porous packing materials was addressed in this work. Characterization of their porous structure was determined to be a key parameter in the prediction of liquid flow through packing materials; the relationship between gland stress and leak rate was also acknowledged. The proposed methodology started by conducting experimental leak measurements with helium gas to characterize the number and size of capillaries. Liquid leak tests with water and kerosene were then conducted in order to validate the predictions. This study showed that liquid leak rates in packed stuffing boxes could be predicted with reasonable accuracy for low gland stresses. It was found that internal pressure and compression stress had an effect on leakage, as did the thickness change and the type of fluid. The measured leak rates were in the range of 0.062 to 5.7 mg/s for gases and 0.0013 and 5.5 mg/s for liquids.

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