The Effect of Partitions on the Laminar Natural Convection in a Square Cavity

2008 ◽  
Author(s):  
Wenjiang Wu ◽  
Chan Y. Ching
Keyword(s):  
Boundary Layer ◽  
Natural Convection ◽  
Secondary Flow ◽  
Rear Surface ◽  
Vertical Wall ◽  
Convection Flow ◽  
Square Cavity ◽  
Flow Circulation ◽  
Laminar Natural Convection ◽  
Layer Flow

The effect of a partition on the laminar natural convection flow in an air-filled square cavity driven by a temperature difference across the vertical walls was investigated experimentally. Two partitions with non-dimensional heights of 0.0625 and 0.125 was attached either to the upper half of the heated vertical wall or the top wall at different locations. The experiments were performed for a global Grashof number of approximately 1.24×108 and non-dimensional top wall temperatures of approximately 0.48 to 2.28. At the higher top wall temperatures, a secondary flow circulation region formed between the partition attached to the top wall and the heated vertical wall of the cavity. This secondary flow circulation region was sensitive to the location and height of the partition, in addition to the top wall temperature of the cavity. The secondary flow circulation region moved the location where the upward boundary layer flow along the heated vertical wall turned over to be further away from the top wall, than in the cavity without the partition. A thermal boundary layer was observed to move along the rear surface of the partition attached to the top wall. In the region close to the top wall, the partitions caused the non-dimensional temperature outside of the boundary layer and the local Nusselt number along the heated vertical wall to be different from that in the cavity without the partition. There were no significant effects of the partition on the flow and heat transfer characteristics in the lower half of the cavity.

Laminar Natural Convection in an Air-Filled Square Cavity With Partitions on the Top Wall

2009 ◽  
Author(s):  
Wenjiang Wu ◽  
Chan Y. Ching
Keyword(s):  
Boundary Layer ◽  
Natural Convection ◽  
Thermal Effect ◽  
Rear Surface ◽  
Vertical Wall ◽  
Square Cavity ◽  
Recirculating Flow ◽  
Vertical Walls ◽  
Laminar Natural Convection ◽  
Temperature And Flow Fields

The laminar natural convection in an air-filled square cavity with a partition on the top wall was experimentally investigated. Temperature measurements and flow visualizations were performed for cases with heated and cooled vertical walls (corresponding to a global Grashof number GrH of approximately 1.3 × 108) and non-dimensional top wall temperatures θT of 0.56 (insulated) to 2.3. Experiments were performed with an aluminum partition with non-dimensional height HP/H of 0.0625 and 0.125 attached to the top wall at x/H = 0.1, 0.2, 0.4 and 0.6. The blockage effect and/or the thermal effect of the partition resulted in changes to the temperature and flow fields, but were mainly limited to the vicinity of the partition. The partition on the heated top wall resulted in a recirculating flow between the partition and the heated vertical wall. For a given partition height, the structure of this recirculating flow was dependent on the partition location and θT. A thermal boundary layer developed along the rear surface of the partition due to the thermal effect of the partition. The ambient temperature outside the boundary layer and Nu near the corner region were affected by the partition height due to the changes in the recirculating flow and due to the thermal effect on the rear surface of the partition.

Natural Convection on Both Sides of a Vertical Wall Separating Fluids at Different Temperatures

1980 ◽  
Vol 102 (4) ◽  
pp. 630-635 ◽  
Author(s):  
R. Anderson ◽  
A. Bejan
Keyword(s):  
Heat Transfer ◽  
Natural Convection ◽  
Thermal Resistance ◽  
Analytical Study ◽  
Vertical Wall ◽  
Conducting Wall ◽  
Different Temperatures ◽  
Laminar Natural Convection ◽  
Layer Flow ◽  
Two Sides

This paper describes an analytical study of laminar natural convection on both sides of a vertical conducting wall of finite height separating two semi-infinite fluid reservoirs of different temperatures. The countercurrent boundary layer flow formed on the two sides is illustrated via representative streamlines, temperature and heat flux distributions. The net heat transfer between reservoirs is reported for the general case in which the wall thermal resistance is not negligible relative to the overall reservoir-to-reservoir thermal resistance.

Efficient Multi-Domain Bivariate Spectral Collocation Solution for MHD Laminar Natural Convection Flow from a Vertical Permeable Flat Plate with Uniform Surface Temperature and Thermal Radiation

2019 ◽  
Vol 16 (06) ◽  
pp. 1840029 ◽  
Author(s):  
Sicelo P. Goqo ◽  
Sabyasachi Mondal ◽  
Precious Sibanda ◽  
Sandile S. Motsa
Keyword(s):  
Natural Convection ◽  
Flat Plate ◽  
Transverse Velocity ◽  
Nonlinear Partial Differential Equations ◽  
Tangential Velocity ◽  
Convection Flow ◽  
Convection Boundary Layer ◽  
Laminar Natural Convection ◽  
Layer Flow ◽  
Steady Laminar

A recently developed numerical method, multidomain quasilinearization, is applied on a steady laminar, natural convection boundary layer flow of MHD viscous and incompressible fluid from a vertical permeable flat plate with uniform temperature in this paper. Nondimensionless variables are used to transform the governing equations to a system of nondimensional nonlinear partial differential equations. Then the resulting equations are solved numerically by using multidomain quasilinearization method. The numerical results for tangential velocity, transverse velocity, and temperature, skin friction are calculated and shown in various tables and graphs.

Influence of undulating wall heat and mass flux on MHD natural convection boundary layer flow from a vertical wall

Heat Transfer ◽  
2020 ◽  
Vol 50 (1) ◽  
pp. 818-848
Author(s):  
Nandita R. Bala ◽  
Shujit K. Bala ◽  
Litan K. Saha ◽  
Md. Anwar Hossain
Keyword(s):  
Boundary Layer ◽  
Natural Convection ◽  
Mass Flux ◽  
Boundary Layer Flow ◽  
Vertical Wall ◽  
Convection Boundary Layer ◽  
Convection Boundary ◽  
Layer Flow

scholarly journals Natural convection flow in a square cavity with internal heat generation and a flush mounted heater on a side wall

2011 ◽  
Vol 7 (2) ◽  
pp. 37-50 ◽  
Author(s):  
Md. Mustafizur Rahman ◽  
M. Arif Hasan Mamun ◽  
M. Masum Billah ◽  
Saidur Rahman
Keyword(s):  
Heat Transfer ◽  
Nusselt Number ◽  
Natural Convection ◽  
Heat Generation ◽  
Vertical Wall ◽  
Heated Wall ◽  
Convection Flow ◽  
Square Cavity ◽  
Natural Convection Flow ◽  
Heater Length

In this study natural convection flow in a square cavity with heat generating fluid and a finite size heater on the vertical wall have been investigated numerically. To change the heat transfer in the cavity, a heater is placed at different locations on the right vertical wall of the cavity, while the left wall is considered to be cold. In addition, the top and bottom horizontal walls are considered to be adiabatic and the cavity is assumed to be filled with a Bousinessq fluid having a Prandtl number of 0.72. The governing mass, momentum and energy equations along with boundary conditions are expressed in a normalized primitive variables formulation. Finite Element Method is used in solution of the normalized governing equations. The parameters leading the problem are the Rayleigh number, location of the heater, length of the heater and heat generation. To observe the effects of the mentioned parameters on natural convection in the cavity, we considered various values of heater locations, heater length and heat generation parameter for different values of Ra varying in the range 102 to 105. Results are presented in terms of streamlines, isotherms, average Nusselt number at the hot wall and average fluid temperature in the cavity for the mentioned parameters. The results showed that the flow and thermal fields through streamlines and isotherms as well as the rate of heat transfer from the heated wall in terms of Nusselt number are strongly dependent on the length and locations of the heater as well as heat generating parameter.DOI: 10.3329/jname.v7i2.3292 

Instability of Laminar Natural Convection Boundary Layer Flow on a Vertical Porous Flat Plate

1996 ◽  
Vol 63 (2) ◽  
pp. 404-410 ◽  
Author(s):  
T. Watanabe ◽  
H. Taniguchi ◽  
I. Pop
Keyword(s):  
Boundary Layer ◽  
Natural Convection ◽  
Boundary Layer Flow ◽  
Convection Boundary Layer ◽  
Injection Parameter ◽  
Convection Boundary ◽  
Porous Flat Plate ◽  
Suction Or Injection ◽  
Laminar Natural Convection ◽  
Layer Flow

The effects of uniform suction and injection on the linear stability theory of laminar natural convection boundary layer flow along a vertical porous flat plate which is maintained at a constant temperature are studied. The nonsimilar boundary layer equations for the basic steady flow have been solved numerically employing a very efficient finite difference scheme in combination with an iterative method for solving the resulting ordinary differential equations. The temporal neutral stability theory for wavelike disturbances of Tollmien-Schlichting type are then presented for the velocity and temperature functions. The corresponding eigenvalue problem for the disturbance amplitude functions is also solved numerically using a very accurate method. Results are presented graphically for both the basic and disturbance velocity and temperature profiles for some values of the modified local Grashof number G and suction or injection parameter X. The Prandtl number Pr is taken to be 0.73 (air) throughout this paper. The results show clearly the important role that suction or injection parameter X may have on the basic and disturbance flow characteristics in this problem.

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