Karim Rahaman

• Doctor of Philosophy
• Professor (Associate) at University of the West Indies, St. Augustine

This study examines the time dependent incompressible fluid flow of a non-Newtonian upper-convected Maxwell, (UCM), fluid within a very long cylinder, which is oscillating in both the longitudinal and torsional directions, with slip occurring at the boundary. Based on the proposed governing equations, analytical expressions are obtained for the vel...

This article explores the passing networks for the most used team formations of Manchester United and Chelsea during the 2016/2017 Premier League Season. A passing matrix is created for each team which distributes the average passes between players in a game. This facilitates the calculation of three centrality measures complementary to those previ...

In this paper, we present an important application of the Hungarian Method - a well-known combinatorial optimization tool for solving assignment problems. For our purposes, we consider the assignment of players to specific roles in a football team. It involves the broad classification of team players as defensive, midfield or attacking, while assig...

During a football game the ball is airborne a large percentage of the time. For this reason it is important to understand to principles that govern the motion of the ball in flight. This paper explores the various equations associated with the movement of the ball in flight. Numeric techniques are utilized to solve some of the equations and represe...

The Bénard–Marangoni thermal instability problem for a viscoelastic Jeffreys’ fluid layer bounded above by a realistic free deformable surface and by a plane surface below is investigated using a linear stability analysis. It has been shown that both the relaxation time and surface deflection have a destabilizing effect unlike the retardation time....

The flow of an Oldroyd-B liquid in a straight, circular, tube oscillating longitudinally and torsionally at different frequencies is examined. The flow does not start from rest but is assumed to be fully established. We obtained analytical solutions for the velocity components which were assumed to have the frequencies of the velocities of the corr...

The creeping motion of a spheroidal particle at the instant it passes the centre of a spherical container has been examined using a general slip condition at the surface of the particle. The shape of the spheroid deviates slightly from that of a sphere at its surface. A first-order expression has been obtained for the stream function characterizing...

The motion of a solid spherical particle at the instant it passes the centre of a spheroidal container has been investigated using the no-slip condition at the surfaces. The shape of this spheroidal container is assumed to deviate slightly from that of a sphere at the surface. An expression for the stream function describing the flow field has been...

The motion of an inner non-Newtonian fluid sphere at the instant it passes the centre of a rigid spherical container is investigated. The inner and outer fluid motions have been determined and the drag on the inner sphere evaluated. Well-known cases are deduced and wall effects then examined.

The main objective of this work is to examine in detail basic unsteady pipe flows and to investigate any new physical phenomena. We take the viscoelastic upper-convected Maxwell fluid as our non-Newtonian model and consider the flow of such a fluid in pipes of uniform circular cross-section in the following three cases: 1.(a) when the pressure grad...