Mathematical modeling of thermal stratification in a double wall cryogenic propellant tank with different insulations using one-dimensional flow over vertical plate approximation

A procedure to predict the complete performance map of turbocharger centrifugal compressors is presented. This is based on a one-dimensional flow analysis using existing published loss correlations that were available and thermodynamic models to describe the incidence loss and slip factor variation at flow rates which differ from the design point. To predict the losses within the complete compressor stage using a one-dimensional flow procedure, it is necessary to introduce a number of empirical parameters. The uncertainty associated with these empirical parameters is assessed by studying the effect of varying them upon the individual losses and upon the overall predicted performance.

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An Evaluation of the Average Flow Model [1] for Surface Roughness Effects in Lubrication

Journal of Lubrication Technology ◽

10.1115/1.3251544 ◽

1980 ◽

Vol 102 (3) ◽

pp. 360-366 ◽

Cited By ~ 23

Author(s):

J. L. Teale ◽

A. O. Lebeck

Keyword(s):

Surface Roughness ◽

Flow Model ◽

Two Dimensional ◽

Roughness Effects ◽

Important Conclusion ◽

Average Flow ◽

One Dimensional ◽

Dimensional Flow ◽

Two Dimensional Flow ◽

Average Flow Model

The average flow model presented by Patir and Cheng [1] is evaluated. First, it is shown that the choice of grid used in the average flow model influences the results. The results presented are different from those given by Patir and Cheng. Second, it is shown that the introduction of two-dimensional flow greatly reduces the effect of roughness on flow. Results based on one-dimensional flow cannot be relied upon for two-dimensional problems. Finally, some average flow factors are given for truncated rough surfaces. These can be applied to partially worn surfaces. The most important conclusion reached is that an even closer examination of the average flow concept is needed before the results can be applied with confidence to lubrication problems.

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Numerical Simulation of Supersonic Combustion in Quasi One-Dimensional Flow

ASME 1991 Computers in Engineering Conference: Volume 1 — Artificial Intelligence; Expert Systems; CAD/CAM/CAE; Computational Fluid/Thermal Engineering ◽

10.1115/cie1991-0085 ◽

1991 ◽

Author(s):

T. Gary Yip

Keyword(s):

Flow Model ◽

Cone Angle ◽

Initial Pressure ◽

Supersonic Combustion ◽

Propulsion Systems ◽

One Dimensional ◽

Hypersonic Propulsion ◽

Dimensional Flow ◽

Conical Shock ◽

Shock System

Abstract Supersonic combustion induced by a two-shock system has been studied using a chemical nonequilibrium, quasi one-dimensional flow model. The combustion of stoichiometric, premixed H2-air is described by a chemistry model which consists of 11 species and 28 reactions. The freestream Mach numbers used in this calculations are 8, 10 and 12. The initial pressure is 0.01 atm and temperature 300 K. The first of the two shocks is a conical shock and the second is its reflection. Supersonic combustion has been predicted to occur at combustor pressures between 0.8 and 2.9 atmospheres, and temperatures between 1500 and 3000 K. The Mach number of the flow in the combustor is between 1.7 and 4. These combustor conditions are typical of the future hypersonic propulsion systems. The results also show the changes in the composition of the flow during the induction and heat release phases. The two-shock system is assumed to be generated by a cone. For Mach 8, 10 and 12, the minimum cone angle for generating a strong enough two-shock system to induce supersonic combustion has also been identified.

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