Experimental and numerical study of O/W emulsion lubricated strip rolling in mixed film regime

2006 ◽  
Vol 25 (1) ◽  
pp. 23-32 ◽  
Author(s):  
A.K. Tieu ◽  
P.B. Kosasih
Author(s):  
P. B. Kosasih ◽  
A. K. Tieu

An experimental and numerical study of cold rolling lubricated by O/W emulsion has been carried out. The experimental measurements are compared to the computed results from the numerical scheme developed by the authors. The scheme, which is based on two-phase lubricant model, is able to calculate oil concentration at any point within the inlet zone and work zone, rolling pressure, film thickness, and fractional contact ratio associated with strip rolling under mixed film lubrication at different rolling speed. The study encompassed extensive mixed film regime for speed, S ranges from 10−5 to 10−1, and supply oil concentration level λds ranges from 1% to 10%, and oil droplet size ranges from Ds from 5 to 20. The numerical results show the occurrence of moderate oil concentration increase in the inlet zone followed by a sharp one at the beginning of the work zone. The effect of the concentration process is predominantly seen in the film thickness and the lubricant pressure whilst its effect on the total pressure is less pronounced. The analysis of the results suggests that it is possible to lower the emulsion oil concentration without detrimental effects on the rolling process and indeed use this principle to control the outlet lubricant film thickness.


2006 ◽  
Vol 39 (12) ◽  
pp. 1591-1600 ◽  
Author(s):  
A.K. Tieu ◽  
P.B. Kosasih ◽  
A. Godbole

2007 ◽  
Vol 40 (5) ◽  
pp. 709-716 ◽  
Author(s):  
P.B. Kosasih ◽  
A.K. Tieu

Author(s):  
Chris Hambidge ◽  
Tom Povey

A numerical study has been conducted to investigate the effects of film cooling on turbine capacity in transonic HP NGVs. The study is part of a wider research program the aim of which is to quantify the sensitivity of capacity predictions to the methods of numerical prediction. Results of two dimensional CFD are presented for the case of single and multiple film cooling rows. The capacity characteristics (with pressure ratio) for modern airfoil profiles, and the change in capacity with film cooling are investigated. The interaction between rows is shown to be weak, and possibility of using superposition techniques is discussed. The effect of turbulence model on the change in capacity with film cooling is discussed. The CFD simulations are compared to a simple analytical two dimensional mixing model developed to aid fundamental understanding of the problem. The effect of film cooling on turbine capacity is modelled by considering a mainstream flow displaced by a partially mixed film cooling layer. The model uses fundamental cooling performance parameters which can be estimated an early stage of the engine design process, providing a means for early assessment of the correction due to film cooling. It is argued that it may be unnecessary to simulate film cooling in capacity predictions.


1998 ◽  
Vol 77 (2) ◽  
pp. 473-484 ◽  
Author(s):  
M. Sampoli, P. Benassi, R. Dell'Anna,

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