scholarly journals Influence of Ferrofluid Lubrication on Longitudinally Rough Truncated Conical Plates with Slip Velocity

2019 ◽  
Vol 7 (2) ◽  
pp. 93-101
Author(s):  
M M Munshi ◽  
A R Patel ◽  
G M Deheri

The study focuses on analyzing the effect of slip velocity in the case of a Ferrofluid squeeze film when the surface of truncated cone-shaped plates has a longitudinal roughness. Each oblique to the bottom plate was utilized by the external magnetic field. The bearing surface has a roughness that is designed with the help of a random stochastic variable having a nonzero mean, skewness and variance. The load carrying ability of a bearing system’s surface is determined by calculating the dispersal of pressure in the system, which is calculated by using the associated stochastically average Reynolds’ equation. The graphs obtained from the study shows that there is a correlation between the longitudinal surface roughness and the bearing system performance. The magnetic fluid lubrication has a positive impact on a system’s bearing capacity. However, the load bearing capacity declines as a result of the effect of slip. A high negative skewness of the surface roughness also has a positive impact on a bearing’s load carrying capacity. One interesting finding shows that contrasting to the results of transverse roughness, standard deviation positively impacts the load bearing capacity. This investigation suggests despite the im-portance of aspect ratio and semi vertical angle is significant for performance enhancement, it is also essential to maintain the slip at the lowest level.

1978 ◽  
Vol 34 (1) ◽  
pp. 25-47 ◽  
Author(s):  
D. R. Oliver ◽  
R. C. Ashton ◽  
G. D. Wadelin

2015 ◽  
Vol 2015 ◽  
pp. 1-9
Author(s):  
G. M. Deheri ◽  
Sejal J. Patel

This investigation analyzes the performance of a magnetic fluid based squeeze film for a sphere in a rough spherical seat with slip velocity. The slip model of Beavers and Joseph has been deployed to study the effect of velocity slip while the stochastic model of Christensen and Tonder has been used to calculate the effect of surface roughness. The concerned statistically averaged Reynolds’ type equation is solved to derive the pressure distribution which results in the calculation of load carrying capacity. The results presented in graphical forms confirm that the adverse effect of slip velocity can be overcome to a large extent at least in the case of negatively skewed roughness. However, lower values of slip may be preferred for enhancing the performance characteristics of the bearing system. Besides, variance (−ve) provides a little support to improve the performance characteristics.


2019 ◽  
Vol 11 (22) ◽  
pp. 6283 ◽  
Author(s):  
Nyncke Hoekstra ◽  
Gertjan Holshof ◽  
René Schils ◽  
Bert Philipsen ◽  
Kees van Reenen ◽  
...  

Due to the increased herd size in the Netherlands, there is need to assess the performance of different grazing systems at high stocking densities. The objective of the current experiment was to assess the effect of two extreme grazing systems, kurzrasen (continuous grazing at 3–5 cm sward height) and strip-grazing at a high stocking rate, on grass production and quality, grass morphology and sward density, root development and load bearing capacity on peat soil. To this end, a two-year grazing trial with four herds of 15 cows on 2 ha each was conducted. Kurzrasen showed 18% lower herbage dry matter production on average compared to strip-grazing. The yield penalty of using a shorter regrowth period under kurzrasen was limited due to the strong response in grass morphology, resulting in a dense and lamina-rich sward. There was a small decline in root density at 10 cm soil depth, but no evidence of a lower root density at 20 cm soil depth for kurzrasen compared to strip-grazing. Sward density was higher for kurzrasen compared to strip-grazing, which had a positive impact on load bearing capacity. This is an important feature on peat soils, where load bearing capacity is often limited.


2015 ◽  
Vol 42 (1) ◽  
pp. 53-71
Author(s):  
Jimit Patel ◽  
G.M. Deheri

This paper analyzes the combined effect of slip velocity and transverse roughness on the performance of a Jenkins model based ferrofluid lubrication of a squeeze film in curved rough annular plates. The slip model of Beavers and Joseph has been invoked to evaluate the effect of slip velocity. In order to find the effect of surface roughness the stochastic averaging model of Christensen and Tonder has been used. The pressure distribution is obtained by solving the concerned stochastically averaged Reynolds type equation. The load carrying capacity is calculated. The graphical representations of the results indicate that the effect of transverse surface roughness is adverse in general, however, the situation is relatively better in the case of negatively skewed roughness. Further, Jenkins model based ferrofluid lubrication offers some measures in reducing the adverse effect of roughness when slip parameter is kept at reduced level with a suitable ratio of curvature parameters. Lastly, the positive effect of magnetization gets a boost due to the combined effect of variance (-ve) and negatively skewed roughness suitably choosing the aspect ratio.


Author(s):  
Jimit R Patel1 ◽  
G M Deheri2

This investigation plans to introduce a correlation among all the three magnetic fluid flow models (Neuringer-Rosensweig’s model, Shliomis’s model, Jenkins’s model) with regards to the conduct of a ferrofluid based curved rough porous circular squeeze film with slip velocity. The Beavers and Joseph's slip velocity has been invoked to assess the impact of slip velocity. Further, the stochastic model of Christensen and Tonder has been utilized to contemplate the impact of surface roughness. The load bearing capacity of the bearing system is found from the pressure distribution which is derived from the related stochastically averaged Reynolds type equation. The graphical portrayals guarantee that Shliomis model might be favoured for preparation of the bearing system with improved life period. However, for lower to moderate values of slip Neuringer-Rosensweig model might be considered. Morever, when the slip is at least the Jenkin's model might be deployed when the roughness is at reduced level.


2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Jimit R. Patel ◽  
Gunamani Deheri

This paper aims to discuss the effect of slip velocity and surface roughness on the performance of Jenkins model based magnetic squeeze film in curved rough circular plates. The upper plate’s curvature parameter is governed by an exponential expression while a hyperbolic form describes the curvature of lower plates. The stochastic model of Christensen and Tonder has been adopted to study the effect of transverse surface roughness of the bearing surfaces. Beavers and Joseph’s slip model has been employed here. The associated Reynolds type equation is solved to obtain the pressure distribution culminating in the calculation of load carrying capacity. The computed results show that the Jenkins model modifies the performance of the bearing system as compared to Neuringer-Rosensweig model, but this model provides little support to the negatively skewed roughness for overcoming the adverse effect of standard deviation and slip velocity even if curvature parameters are suitably chosen. This study establishes that for any type of improvement in the performance characteristics the slip parameter is required to be reduced even if variance (−ve) occurs and suitable magnetic strength is in force.


Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3557
Author(s):  
Mariusz Wesołowski ◽  
Piotr Włodarski ◽  
Paweł Iwanowski ◽  
Agata Kowalewska

The load-bearing capacity of natural airfield pavement has a direct impact on the safety of air operations. Unfortunately, the field tests often indicate that the load-bearing capacity of natural airfield pavements is not sufficient. In this case, it is necessary to reinforce them in order to meet the requirements set out in international documents. It is important that the method of reinforcing the subsoil is fast and as noninvasively as possible. There are many methods of reinforcing the subsoil, however, they are expensive and time-demanding, which involves turning off the airport for a long time. Airfield geocells made of recycled plastics discussed in the article seem to be the optimal solution due to the quick implementation of their application by pressing into the existing natural pavement. The article presents the results of laboratory tests demonstrating that material in question is load-resistant and chemical-resistant, while field studies have confirmed that the airfield geocell made of the plastic in question improves the load carrying capacity of natural airfield pavement.


Buildings ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 512
Author(s):  
Miroslav Rosmanit ◽  
Přemysl Pařenica ◽  
Oldřich Sucharda ◽  
Petr Lehner

Thin-walled cold-rolled sections are used in the construction industry, especially in the roofing of large-span halls. The load-bearing capacity of a thin-walled structure depends to a large extent on the load-bearing capacity of the details at the point of attachment to the structure and the interconnection of the individual thin-walled elements. Therefore, in the case of thin-walled structures, it is necessary to use additional structural elements such as local reinforcement, stabilising elements, supports, and other structural measures such as the doubling of profiles. This paper focused on the behaviour of tall Z300 and Z350 mm thin-walled trusses at the connection to the superstructure regarding upward loading (e.g., wind suction and so on). Two section thicknesses, 1.89 mm and 2.85 mm, were experimentally analysed. Furthermore, two types of connections were prepared, more precisely without and with a reinforced buckle. The experiments aimed to investigate the behaviour and load-carrying capacity of the detail of the roof truss connections to the supporting structure. The resulting load capacity values were compared with normative approaches. Analyses of the details of the bolt in the connection are also presented. The paper presents a practical evaluation of the physical test on real structural members.


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