Numerical prediction of windage power losses for a spur gear in two phase media

2018 ◽  
Author(s):  
Murat K. Aktas ◽  
A.K. Ersan ◽  
M.A. Yavuz
Keyword(s):  
Spur Gear ◽  
Numerical Prediction ◽  
Power Losses ◽  
Two Phase

scholarly journals Numerical Prediction of Two-Phase Flow in Tube Bundles with a CFD Porous Media Approach Based on Mixture Model and a Void Fraction Correlation

2021 ◽  
Vol 321 ◽  
pp. 01002
Author(s):  
Claire Dubot ◽  
Vincent Melot ◽  
Claudine Béghein ◽  
Cyrille Allery ◽  
Clément Bonneau
Keyword(s):  
Porous Media ◽  
Mixture Model ◽  
Void Fraction ◽  
Two Phase Flow ◽  
Numerical Prediction ◽  
Phase Flow ◽  
Two Phase ◽  
Mixture Density ◽  
Tube Bundles ◽  
Phase Mixture

Being able to predict the void fraction is essential for a numerical prediction of the thermohydraulic behaviour in steam generators. Indeed, it determines two-phase mixture density and affects two-phase mixture velocity which enable to evaluate the pressure drop of heat exchanger, the mass transfer and heat transfer coefficients. In this study, the flow is modelled by coupling Ansys Fluent with an in-house code library where a CFD porous media approach is implemented. In this code, the two-phase flow has been modelled so far using the Eulerian model. However, this two-phase model requires interaction laws between phases which are not known and/or reliable for a flow within a tube bundle. The aim of this paper is to use the mixture model, for which it is easier to implement suitable correlations for tube bundles. By expressing the relative velocity, as a function of slip, the void fraction model of Feenstra et al. developed for upward cross-flow through horizontal tube bundles is introduced. With this method, physical phenomena that occur in tube bundles are taken into consideration in the mixture model. The developed approach is validated based on the experimental results obtained by Dowlati et al.

An Experimental Methodology to Determine Components of Power Losses of a Gearbox

2021 ◽  
Vol 143 (11) ◽  
Author(s):  
A. Dindar ◽  
K. Chaudhury ◽  
I. Hong ◽  
A. Kahraman ◽  
C. Wink
Keyword(s):  
Power Loss ◽  
Spur Gear ◽  
Rolling Element Bearing ◽  
Experimental Methodology ◽  
Total Power ◽  
Gear Pair ◽  
Rolling Element Bearings ◽  
Power Losses ◽  
Rolling Element ◽  
The One

Abstract In this study, an experimental methodology is presented to separate various components of the power loss of a gearbox. The methodology relies on two separate measurements. One is designed to measure total power loss of a gearbox housing a single spur gear pair under both loaded and unloaded conditions such that load-independent (spin) and load-dependent (mechanical) components can be separated. With the assumption that gear pair and rolling element bearings constitute the bulk of the gearbox power loss, a second measurement system designed to quantify rolling element bearing losses is proposed. With this setup, spin and mechanical power losses of rolling element bearings used in the gearbox experiments are measured. Combining the sets of gearbox and bearing data, power loss components attributable to the gear pair and rolling element bearings are quantified as a function of speed and torque. The results indicate that all gear and bearing related components are significant and a methodology such as the one proposed in this study is warranted.

Oil Churning Power Losses of a Gear Pair: Experiments and Model Validation

2009 ◽  
Vol 131 (2) ◽  
Author(s):  
S. Seetharaman ◽  
A. Kahraman ◽  
M. D. Moorhead ◽  
T. T. Petry-Johnson
Keyword(s):  
Power Loss ◽  
Spur Gear ◽  
Companion Paper ◽  
Design Parameters ◽  
Measured Parameter ◽  
Gear Pair ◽  
Power Losses ◽  
Gear Design ◽  
Face Width ◽  
Wide Range

This paper presents the results of an experimental study on load-independent (spin) power losses of spur gear pairs operating under dip-lubricated conditions. The experiments were performed over a wide range of operating speed, temperature, oil levels, and key gear design parameters to quantify their influence on spin power losses. The measurements indicate that the static oil level, rotational speed, and face width of gears have a significant impact on spin power losses compared with other parameters such as oil temperature, gear module, and the direction of gear rotation. A physics-based gear pair spin power loss formulation that was proposed in a companion paper (Seetharaman and Kahraman, 2009, “Load-Independent Spin Power Losses of a Spur Gear Pair: Model Formulation,” ASME J. Tribol., 131, p. 022201) was used to simulate these experiments. Direct comparisons between the model predictions and measurements are provided at the end to demonstrate that the model is capable of predicting the measured spin power loss values as well as the measured parameter sensitivities reasonably well.

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