Analysis of Squeeze Films Between Rough Circular Plates Lubricated with Rabinowitsch Fluids
Issue:
Volume 7, Issue 1, March 2019
Pages:
1-9
Received:
12 May 2019
Accepted:
10 June 2019
Published:
25 June 2019
Abstract: The present theoretical work investigates the combined impacts of non-Newtonian (pseudoplastic and dilatant) lubricants and surface roughness on the performance of squeeze films lubrication between two rough circular plates. The modified Reynolds equation has been derived on the basis of Christensen’s stochastic theory of hydrodynamic lubrication for rough surfaces. The lubricant model adopted for the analysis is Rabinowitsch fluid model – an experimentally verified fluid model for lubricated bearing systems. Two types of one-dimensional roughness patterns (radial and azimuthal) have been considered in the analysis. An asymptotic solution for squeeze film pressure, load carrying capacity and squeeze film time are obtained. The numerical results for dimensionless film pressure, load carrying capacity and film squeezing time have been calculated for various values of fluid and operating parameters. The results for dimensionless film pressure, load capacity and squeezing time of the lubricant film have been discussed with clear graphical presentation for different values of parameters of pseudoplasticity and roughness. It was observed that the radial roughness decreases the film pressure, load capacity and squeezing time of lubricant, while increased values of these properties were observed for azimuthal roughness. It was also observed that the pseudoplastic lubricants decrease the film pressure and load capacity, while the dilatant lubricants increase these properties. Also, the variations in these results are highly significant.
Abstract: The present theoretical work investigates the combined impacts of non-Newtonian (pseudoplastic and dilatant) lubricants and surface roughness on the performance of squeeze films lubrication between two rough circular plates. The modified Reynolds equation has been derived on the basis of Christensen’s stochastic theory of hydrodynamic lubrication f...
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Effect on Strength of Concrete by Partial Replacement of Ordinary Portland Cement with Silica Fume
Farhan Hussain Wagan,
Naila Qadir Hisbani,
Ghulam Hussain Wagan
Issue:
Volume 7, Issue 1, March 2019
Pages:
10-14
Received:
9 May 2019
Accepted:
13 June 2019
Published:
26 June 2019
Abstract: Now a days, the increased use of scrap/waste as construction material has proved to be very harmful for the environment particularly in tropical countries like Pakistan. Researchers are trying at their best to reduce the adverse impact of waste material on the required environment but yet until more work is required in this regard. In this research paper authors have tried to reuse Silica Fume as construction material as it is very easily available in market as waste material from raw material /by- product industrial waste materials used in mills. The Authors obtained silica fume after proper screening the concerned industrial waste. These industries are available in grater quantity in the province of sindh. The required waste material is available in huge quantity. Silica is very important construction material and by using this as waste we can protect our environment by reusing or proper use of waste material. Here, researchers took different percentage of silica fume and mixed with concrete in varying ratio as replacement of Ordinary Portland Cement as active material in laboratory. Results were came, very interesting and found Tensile Strength, Compressive Strength and Flexural Strengths near to Ordinary Portland Cement also other properties of concrete like pH value, Slump, Curing and Temperature of Concrete shows satisfactory results at various percentage of Replacement with Ordinary Portland Cement. The research work has yielded the satisfactory results and the silica fume can be used effectively as an active construction material. Different percentage shows different results but at 5% and 10% mixing of silica fume indicated high strength as compare to ordinary cement mix and the controlled temperature 280c. Further, Engineering is a vast field and it needs more research with passage of time.
Abstract: Now a days, the increased use of scrap/waste as construction material has proved to be very harmful for the environment particularly in tropical countries like Pakistan. Researchers are trying at their best to reduce the adverse impact of waste material on the required environment but yet until more work is required in this regard. In this research...
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