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Rama Krishna Prasad, K.
- Analysis of Load Carrying Capacity in Finite Hydrodynamic Spiral Journal Bearing - Operating with Micro Polar Fluid
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Authors
Affiliations
1 Dept. of Mathematics, S. V. University, Tirupati, IN
2 Y. S. R. Engg. College of Yogi Vemana University, Proddatur, IN
1 Dept. of Mathematics, S. V. University, Tirupati, IN
2 Y. S. R. Engg. College of Yogi Vemana University, Proddatur, IN
Source
Manufacturing Technology Today, Vol 12, No 8 (2013), Pagination: 6-16Abstract
Hydrodynamic journal bearing with circular cross section when used in high speed rotating machinery such as Turbines, Compressors, Pumps, Engine cranks and Large Milling systems, etc., often face the problem of instability. In such high speed machinery non-circular bearings are widely used to support the oil whirl. The present paper focuses on one of the non-circular bearings called Spiral Bearing. It is also well known that additives are added to the base lubricant to improve its lubricating properties. If additives are in the form of particles at low concentration a micro polar fluid may characterized the resulting fluid. Based on the micro polar theory a theoretical analysis on the load carrying capacity of finite spiral bearing operating with micro polar fluid is presented. The modified Reynolds Equation is obtained based on the theory of micro polar fluids. The film pressure distribution equation is numerically solved by using Finite Difference Technique. According to the results the micro polar effects exhibit increase in load carrying capacity. The spiral bearing is having more load carrying capacity than circular bearing.Keywords
Hydrodynamic Journal Bearing, Spiral Bearing, Micro Polar Fluid and Static Characteristic.- Analysis of Load Carrying Capacity in Finite Porous Squeeze Film Bearings by Rapid Technique
Abstract Views :172 |
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Authors
Affiliations
1 K. S. R. M. College of Engg., Kadapa, IN
2 S. V. U. College of Engg., Tirupati, IN
1 K. S. R. M. College of Engg., Kadapa, IN
2 S. V. U. College of Engg., Tirupati, IN
Source
Manufacturing Technology Today, Vol 6, No 10 (2007), Pagination: 3-9Abstract
Porous bearings have an advantage over conventional sleeve bearings, in which no external supply of lubricant is necessary for their satisfactory operation for long periods. These can operate as self-acting bearings; squeeze film bearings or externally pressurized bearings. Squeeze film is a phenomenon of two lubricated surfaces approaching each other with a normal velocity. The thin film of lubricant between the two surfaces acts as a cushion and prevents the surfaces making instantaneous contact. Generally, the pressure distribution in this fluid film is determined by using numerical methods. In the present analysis, a modified Reynolds equation has been developed by combining the Reynolds equation and the Laplace equation for the finite porous squeeze film bearing. The load carrying capacity is studied by solving this modified Reynolds equation using Rapid Technique. The results are shown graphically for selected parameter values. The results indicate, as the L/D ratio, and or eccentricity ratio increases, load carrying capacity increases but as the permeability parameter increases load carrying capacity decreases. For highly porous bearings, the squeezing effects are not significant. The obtained results are compared with the short bearing and solid bearing analysis.- Studies on Heterosis and Combining Ability in Rice (Oryza sativa L.)
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Authors
Affiliations
1 Department of Genetics and Plant Breeding, Agricultural College, Bapatla (A.P.), IN
2 Regional Agricultural Research Station, Maruteru, West Godavari (A.P.), IN
1 Department of Genetics and Plant Breeding, Agricultural College, Bapatla (A.P.), IN
2 Regional Agricultural Research Station, Maruteru, West Godavari (A.P.), IN
Source
International Journal of Agricultural Sciences, Vol 15, No 1 (2019), Pagination: 60-66Abstract
Hybrid vigour and combining ability of two lines, 25 testers and their 50 hybrids was studied for grain yield, yield components and quality parameters during Rabi 2017-18. A perusal of the results revealed that the expression of heterosis was maximum over mid-parent for grain yield plant-1 and number of grains panicle-1 (>90%). Grain yield plant-1 and number of grains panicle-1 had also recorded high levels of heterosis over better parent (>70%). Standard heterosis more than 50 per cent was also recorded for grain yield plant-1 and number of grains panicle-1over both varietal and the hybrid check. Further, combining ability analysis revealed pre-ponderant non-additive gene action for all the traits studied. A perusal of the GCA effects revealed MTU 2247-55-2, JMP 16, MTU 2336-70-46-25-44, MTU 2336-62-25-39-16, MTU 2337-216-1-1 and MTU 2331-216-1-1 to be good combiners for grain yield plant-1 and quality parameters. Analysis of the specific combining ability effects revealed none of the hybrids to possess consistently high SCA effects for all the characters and the best cross combination was observed to vary from character to character. Further, nine hybrids had recorded high per se performance, heterosis and desirable SCA effects for grain yield plant-1. Among these three hybrids, APMS 8A x MTU 2247-55-2, APMS 8A x MTU 2331-216-1-1 and APMS 8A x MTU 2337-216-1-1 involving poor and good combiner parents for grain yield plant-1, had recorded maximum grain yield plant-1, in addition to desirable SCA effects and standard heterosis >50 per cent for grain yield plant-1.Keywords
Heterosis, Combining Ability, Grain Yield, Quality, Rice.References
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