G. Alexander Raymand

Bio: G. Alexander Raymand is an academic researcher from Sri Sivasubramaniya Nadar College of Engineering. The author has contributed to research in topics: Thrust bearing & Lubrication. The author has an hindex of 1, co-authored 4 publications receiving 4 citations.

Core Variation in an Externally Pressurized Converging Thrust Bearing with Bingham Lubricant

Abstract: The effects of angle of convergence on the shape and thickness of the core are analyzed theoretically by considering variable film thickness in an externally pressurized circular thrust bearing. Using the assumptions of the lubrication theory, modified Reynold’s equation and the governing equations are obtained. Using the boundary conditions of the problem in the constitutive equations we get the velocity of the core region as well as flow region. By considering the equilibrium of an element in the yield surface, an algebraic equation to determine the thickness of the yield surface is derived. Numerical solutions are obtained for the thickness of yield surface and velocities for various values of Bingham Numbers and the angle of convergence.

Inertia Effects in Rheodynamic Lubrication of an Externally Pressurized Converging Thrust Bearing using Bingham Fluids

Abstract: Thrust bearing are innately developed to withstand axial load. When the bearing is subjected to high speed operations, heavy load, high stiffness etc., suggesting a change in the design of the bearing plays a vital role in its performance. Friction is developed between the circular plates while the bearing operates. To reduce this friction, the bearing is lubricated with lubricants such as mineral oil, greases etc., Generally, lubricants are classified into two types that is Newtonian and non-Newtonian. However, non-Newtonian fluids characterized by an yield value such as Bingham, Casson and Herschel Bulkley, are attracting the tribologists, at present. And also, the study of fluid inertia on thrust bearing is required to optimize the performance of the bearings. In this investigation, we have ventured to analyze the performance of the bearing by considering the combined effects of fluid inertia forces and non-Newtonian characteristic with Bingham fluid as lubricant in an externally pressurized converging circular thrust bearing. Such studies will be useful in the design of the bearing for the optimum performance using the appropriate lubricant in various machineries operating in an extreme condition in the industries. Averaging the inertia terms over film thickness and defining a modified pressure gradient, the rheodynamic lubrication equation containing inertia terms has been analyzed. Using the appropriate boundary conditions and considering externally pressurized flow in narrow clearance between two converging discs is symmetric w.r.t r and z axis, the velocity distributions, the modified pressure gradient and thereby the film pressure and the load capacity of the bearing have been obtained numerically for different values of Bingham number, Reynolds number and angle of convergence. In addition to that, the effects of the inertia forces, non-Newtonian characteristics and angle of convergence on the bearing performances have been discussed.

Rheodynamic Lubrication of an Externally Pressurized Converging Circular Thrust Bearing Using Viscoplastic Fluids

Abstract: In this research paper, we have theoretically analyzed the effects of the angle of convergence and the non-Newtonian characteristics on the performance of an externally pressurized converging circular thrust bearing using Bingham and Casson fluids as a lubricant. Since the two non-Newtonian lubricants are known to have a characterized yield value, there will be a formation of unyielding core in the region between the plates of the bearing. The numerical solutions are obtained for the core thickness, pressure, and load-carrying capacity of the bearing for various values of Bingham and Casson number and for the various angle of convergence. The effects of the non-Newtonian characteristics of the lubricants and the angle of convergence on the performance of the bearing are discussed.

Analysis of Externally Pressurized Thrust Bearing with Inclination Angle Using Yield Stress Fluids

Abstract: In this investigation, the effects of the non-Newtonian characteristics and angle of inclined plane (ɸ) of the externally pressurized bearing lubricated with yield stress fluid is studied. We have obtained mathematical formulation for varying film thickness. Applying appropriate boundary conditions and numerical procedure, the governing equations are solved iteratively. There is a formation of an unyielding core in the flow region for yield stress fluids, and the shape and size of this core have been calculated numerically. Further, the effects of the angle of inclined plane (ɸ) and non-Newtonian characteristic on pressure distribution and load capacity are discussed.

Inertia Effects in Rheodynamic Lubrication of an Externally Pressurized Converging Thrust Bearing using Bingham Fluids

Abstract: Thrust bearing are innately developed to withstand axial load. When the bearing is subjected to high speed operations, heavy load, high stiffness etc., suggesting a change in the design of the bearing plays a vital role in its performance. Friction is developed between the circular plates while the bearing operates. To reduce this friction, the bearing is lubricated with lubricants such as mineral oil, greases etc., Generally, lubricants are classified into two types that is Newtonian and non-Newtonian. However, non-Newtonian fluids characterized by an yield value such as Bingham, Casson and Herschel Bulkley, are attracting the tribologists, at present. And also, the study of fluid inertia on thrust bearing is required to optimize the performance of the bearings. In this investigation, we have ventured to analyze the performance of the bearing by considering the combined effects of fluid inertia forces and non-Newtonian characteristic with Bingham fluid as lubricant in an externally pressurized converging circular thrust bearing. Such studies will be useful in the design of the bearing for the optimum performance using the appropriate lubricant in various machineries operating in an extreme condition in the industries. Averaging the inertia terms over film thickness and defining a modified pressure gradient, the rheodynamic lubrication equation containing inertia terms has been analyzed. Using the appropriate boundary conditions and considering externally pressurized flow in narrow clearance between two converging discs is symmetric w.r.t r and z axis, the velocity distributions, the modified pressure gradient and thereby the film pressure and the load capacity of the bearing have been obtained numerically for different values of Bingham number, Reynolds number and angle of convergence. In addition to that, the effects of the inertia forces, non-Newtonian characteristics and angle of convergence on the bearing performances have been discussed.

Inertia Effects in the Planar Squeeze Flow of a Bingham Fluid: A Matched Asymptotics Analysis

Abstract: The effects of inertia on the squeeze flow of a Bingham fluid between two approaching parallel plates with a constant squeeze velocity is investigated using matched asymptotic expansions. This analysis is an extension to the prior study of Muravleva (2015), who has investigated the planar squeeze flow of a Bingham fluid in the absence of inertia. In the present study, the expressions for the shear stress field, velocity, pressure field and squeeze force are derived. The combined effects of the fluid inertia and yield stress on the pressure field and squeeze force are investigated. We found that the pressure and eventually squeeze force increases with increase in Reynolds number. The squeeze force decreases with an increase in the value of the gap aspect ratio.

Rheodynamic Lubrication of an Externally Pressurized Converging Circular Thrust Bearing Using Viscoplastic Fluids

Abstract: In this research paper, we have theoretically analyzed the effects of the angle of convergence and the non-Newtonian characteristics on the performance of an externally pressurized converging circular thrust bearing using Bingham and Casson fluids as a lubricant. Since the two non-Newtonian lubricants are known to have a characterized yield value, there will be a formation of unyielding core in the region between the plates of the bearing. The numerical solutions are obtained for the core thickness, pressure, and load-carrying capacity of the bearing for various values of Bingham and Casson number and for the various angle of convergence. The effects of the non-Newtonian characteristics of the lubricants and the angle of convergence on the performance of the bearing are discussed.

Analysis of Externally Pressurized Thrust Bearing with Inclination Angle Using Yield Stress Fluids

Abstract: In this investigation, the effects of the non-Newtonian characteristics and angle of inclined plane (ɸ) of the externally pressurized bearing lubricated with yield stress fluid is studied. We have obtained mathematical formulation for varying film thickness. Applying appropriate boundary conditions and numerical procedure, the governing equations are solved iteratively. There is a formation of an unyielding core in the flow region for yield stress fluids, and the shape and size of this core have been calculated numerically. Further, the effects of the angle of inclined plane (ɸ) and non-Newtonian characteristic on pressure distribution and load capacity are discussed.