Begell House Inc.
International Journal of Fluid Mechanics Research
FMR
2152-5102
36
3
2009
Stokes' Second Problem for a Micropolar Fluid Through State-Space Approach
193-206
M.
Devakar
Department of Mathematics, Visvesvaraya National Institute of Technology, Nagpur-440 010, India
T. K. V.
Iyengar
Department of Mathematics, National Institute of Technology, Warangal-506004, Andhra Pradesh, India
This paper deals with Stokes' second problem for an incompressible micropolar fluid. The flow is produced by a plane boundary moving in its own plane with a sinusoidal variation of velocity. The flow field variables are obtained through state-space technique. Laplace transform of the flow variables in the time domain is taken and the inversion of Laplace transform is carried out using a numerical approach. The variation of velocity and microrotation fields is studied with respect to various flow parameters and the results are presented through graphs.
Fluctuating Free Convection Flow Along Heated Horizontal Circular Cylinders
207-230
Anwar
Hossain
Department of Mathematics, University of Dhaka, Dhaka-1000, Bangladesh
Md.
Kamrujjaman
Department of Mathematics, University of Dhaka, Dhaka-1000, Bangladesh
Rama Subba Reddy
Gorla
Department of Mechanical Engineering, Cleveland State University, Cleveland, OH, 44115 USA; Department of Mechanical Engineering, University of Akron, Akron, Ohio 44325, USA; Department of Mechanical & Civil Engineering, Purdue University Northwest, Westville, IN 46391, USA
Unsteady free convection flow of a viscous incompressible fluid along an infinite horizontal cylinder with a small-amplitude oscillation of the surface temperature about a mean temperature has been investigated. Using appropriate transformations, the governing equations reduced to local nonsimilarity equations for both the steady and unsteady parts of the solutions, which are obtained numerically employing the implicit finite difference method together with the Keller box elimination scheme. The effects of pertinent parameters, such as the Strouhal number, St, and the Prandtl number, Pr, on the local fluctuating skin-friction and heat transfer coefficients as well as on their amplitude and phase are shown graphically on the entire surface of the cylinder 0 ≤ x ≤ π.
Wind Loads on Low-Rise Building Models with Different Roof Configurations
231-243
Deepak
Prasad
School of Engineering and Physics, Faculty of Science and Technology, The University of the South Pacific, Suva, Fiji
Tuputa
Uliate
School of Engineering and Physics, Faculty of Science and Technology, The University of the South Pacific, Suva, Fiji
M. Rafiuddin
Ahmed
School of Engineering and Physics, Faculty of Science and Technology, The University of the South Pacific, Suva, Fiji
Wind tunnel testing of low-rise building models with flat, gabled and hip roof configurations was carried out in a boundary layer wind tunnel. All the models had the same mean height. For the gabled and the hip roofs, the pitch angles investigated were 15, 20, 30 and 45°. Pressure measurements were performed on all the walls and the roof of the building models facing a turbulent wind of 7 m/s and the values of pressure coefficient were calculated. It was found that the suction over the roof is significantly influenced by the roof configuration. The 45° gabled and hip building models performed the best under the same wind conditions. The peak suction over the roof reduces by 85 and 91%, respectively, compared to that over the flat roof. In addition to this, the hip roof models recorded less suction compared to their gabled counterparts. For the hip roof, the peak suction reduced by 42% compared to the gabled roof.
Peristaltic Transport of a Casson Fluid in Contact with a Newtonian Fluid in a Circular Tube with Permeable Wall
244-254
Kuppalapalle
Vajravelu
University of Central Florida
S.
Sreenadh
Department of Mathematics, Sri Venkateswara University Tirupati 517502, India
R. Hemadri
Reddy
Department of Mathematics, Sri Venkateswara University Tirupati 517502, India
K.
Murugesan
Department of Mathematics, National Institute of Technology Tiruchirapalli 620015, India
We investigate the flow of a Casson fluid in contact with a Newtonian fluid in a circular pipe with permeable wall. The motion is caused by the movement of peristaltic waves on the flexible walls of the channel. The equation of the interface is obtained and its variation with the yield stress is discussed. The effects of yield stress and permeability on the pumping characteristics are studied in detail. Moreover, when the limit of the permeability parameter α and the yield stress τ0 → 0, our results agree with those of Rao and Usha [25] for the peristaltic transport of two immiscible Newtonian fluids in a circular tube with an impermeable flexible wall. Furthermore, the results obtained for the flow characteristics reveal many interesting behaviors that warrant further study of the peristaltic transport models with physiological fluids, especially the shear-thinning fluids. Shear thinning reduces the wall shear stress.
Fluid Flow and Heat Transfer Studies and Correlations for Mixed Convection with Conduction and Radiation from a Discretely Heated Vertical Plate
255-271
S. M.
Sawant
Department of Mechanical Engineering, National Institute of Technology Warangal-506004 (A.P.) India
C. Gururaja
Rao
Department of Mechanical Engineering, National Institute of Technology Warangal-506004 (A.P.) India
The article provides the results and correlations pertaining to fluid flow and heat transfer for the problem of mixed convection with conduction and radiation from the fundamental geometry of a vertical plate heated discretely using three identical flush-mounted heat sources. The cooling medium considered is air. Finite volume method has been used to solve the governing continuity, Navier-Stokes and energy equations without boundary layer approximations considered in stream function − vorticity form. A computational domain with 151 grids along and 111 grids across the plate has been chosen. The nature of variation of the local drag coefficient, mean friction coefficient, contributions to mean friction coefficient and plate heat dissipation from free convection, forced convection and radiation. A comparative study between uniformly and discretely heated vertical plate geometries for the identical net heat dissipation has been made. Based on a large set of 583 data generated from the computer code written for solving the present problem, correlations for non-dimensional maximum and average plate temperature and mean friction coefficient have been evolved.
Natural Convection Laminar Flow with Temperature Dependent Viscosity and Thermal Conductivity Along a Vertical Wavy Surface
272-288
Md. Mamun
Molla
School of Engineering & Applied Science, Dept. of Electrical & Computer Engineering, North South University Dhaka-1229, Bangladesh
Rama Subba Reddy
Gorla
Department of Mechanical Engineering, Cleveland State University, Cleveland, OH, 44115 USA; Department of Mechanical Engineering, University of Akron, Akron, Ohio 44325, USA; Department of Mechanical & Civil Engineering, Purdue University Northwest, Westville, IN 46391, USA
Natural convection laminar flow of a viscous incompressible fluid along a uniformly heated vertical wavy surface with temperature dependent viscosity and thermal conductivity has been investigated. We consider the boundary layer regime when the Grashof number Gr is large. Using the appropriate transformation variables, the basic governing equations are first transformed to non-similar boundary layer form and then solved numerically employing the implicit finite difference method together with Keller-box scheme. The numerical results are presented in terms of the streamlines and isotherms as well as the fluid flow and heat transfer characteristics, namely, the local skin-friction coefficient and the local Nusselt number for a wide range of values of the viscosity and thermal conductivity variation parameter, surface waviness and the Prandtl number.