Scaling and Integral Solutions to Mixed Convection Over an Exponential Stretching Sheet

The reported studies on mixed convection flow problems have been solved purely by method of similarity studies. Scaling analysis is an alternate method that can give better engineering insight of the problem being investigated. Integral solutions are mathematically simpler to handle as the engineering requirement is that of accurate solutions only close to the wall. In the present work, scaling and integral solutions are discussed for a typical mixed convection flow problem already discussed in literature by similarity technique. Scaling method has been demonstrated and is found in good agreement with the results obtained from similarity method. The integral solution is obtained by deriving the integral form of governing equation and solution is discussed for specific case of Prandtl number = 1. The solution obtained by Integral formulations is in good agreement with that of similarity method.

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Thermal ignition of a combustible over an inclined hot plate

SN Applied Sciences ◽

10.1007/s42452-021-04363-4 ◽

2021 ◽

Vol 3 (3) ◽

Author(s):

Salaika Parvin ◽

Nepal Chandra Roy ◽

Rama Subba Reddy Gorla

Keyword(s):

Mixed Convection ◽

Convection Flow ◽

Physical Parameters ◽

Thermal Ignition ◽

Mixed Convection Flow ◽

Flow Properties ◽

Continuous Transformation ◽

Hot Plate ◽

Ignition Characteristics ◽

Good Agreement

AbstractIn this study, the ignition characteristics and the flow properties of the mixed convection flow are presented. Detailed formulations of the forced, natural and mixed convection problems have been discussed. In order to avoid inconvenient switch between the forced and natural convection we introduce a continuous transformation in the mixed convection. We make a comparison between these situations which reveal a good agreement. For mixed convection flow, the ignition distance is explicitly expressed as a function of the Prandtl number, reaction parameter and wall temperature. It has been observed that owing to the increase of the aforesaid parameters, the thermal ignition distance is reduced. Numerical results are illustrated for velocity, temperature, and concentration for different physical parameters. Furthermore, the development of combustion is presented by using streamlines, isotherms and isolines of fuel and oxidizer.

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Measurements and Predictions of Laminar Mixed Convection Flow Adjacent to a Vertical Surface

Journal of Heat Transfer ◽

10.1115/1.3247471 ◽

1985 ◽

Vol 107 (3) ◽

pp. 636-641 ◽

Cited By ~ 53

Author(s):

N. Ramachandran ◽

B. F. Armaly ◽

T. S. Chen

Keyword(s):

Free Convection ◽

Mixed Convection ◽

Flat Surface ◽

Vertical Surface ◽

Convection Flow ◽

Mixed Convection Flow ◽

Nusselt Numbers ◽

Buoyancy Parameter ◽

Laminar Mixed Convection ◽

Good Agreement

Measurements and predictions of laminar mixed forced and free convection air flow adjacent to an isothermally heated vertical flat surface are reported. Local Nusselt numbers and the velocity and temperature distributions are presented for both the buoyancy assisting and opposing flow cases over the entire mixed convection regime, from the pure forced convection limit (buoyancy parameter ξ = Grx/Rex2 = 0) to the pure free convection limit (ξ = ∞). The measurements are in very good agreement with predictions and deviate from the pure forced and free convection regimes for buoyancy assisting flow in the region of 0.01 ≤ ξ ≤ 10 and for opposing flow in the region of 0.01<ξ< 0.2. The local Nusselt number increases for buoyancy assisting flow and decreases for opposing flow with increasing value of the buoyancy parameter. The mixed convection Nusselt numbers are larger than the corresponding pure forced and pure free convection limits for buoyancy assisting flow and are smaller than these limits for opposing flow. For buoyancy assisting flow, the velocity overshoot and wall shear stress increase, whereas the temperature decreases but the temperature gradient at the wall increases as the buoyancy parameter increases. The reverse trend is observed for the opposing flow. Flow reversal near the wall was detected for the buoyancy opposing flow case at a buoyancy parameter of about ξ = 0.20.

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Minimization of Entropy Generation in MHD Mixed Convection Flow with Energy Dissipation and Joule Heating: Utilization of Sparrow-Quack-Boerner Local Non-Similarity Method

Defect and Diffusion Forum ◽

10.4028/www.scientific.net/ddf.387.63 ◽

2018 ◽

Vol 387 ◽

pp. 63-77 ◽

Cited By ~ 4

Author(s):

M. Idrees Afridi ◽

Muhammad Qasim ◽

Najeeb Alam Khan ◽

Oluwole Daniel Makinde

Keyword(s):

Energy Dissipation ◽

Mixed Convection ◽

Entropy Generation ◽

Joule Heating ◽

Convection Flow ◽

Physical Parameters ◽

Mixed Convection Flow ◽

Entropy Analysis ◽

Entropy Generation Number ◽

Similarity Method

This article aims to present the non-similar solution of MHD mixed convection flow using the Sparrow-Quack-Boerner local non-similarity method. Entropy analysis is also performed in the presence of energy dissipation and Joule heating. The buoyancy parameter is chosen as the non-similarity variable and the equations are derived up to the second level of truncation. The dependency of dimensionless velocity profile, temperature distribution, Bejan and entropy generation number on physical parameters has been discussed. As far as the knowledge of the authors is concerned, no attempt has been made on the entropy analysis of MHD mixed convection flow by the local non-similarity method.

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Viscous dissipation effect on mixed convection flow of a micropolar fluid over an exponentially stretching sheet

Canadian Journal of Physics ◽

10.1139/p09-047 ◽

2009 ◽

Vol 87 (4) ◽

pp. 359-368 ◽

Cited By ~ 60

Author(s):

Mohamed Abd El-Aziz

Keyword(s):

Heat Transfer ◽

Boundary Layer ◽

Mixed Convection ◽

Viscous Dissipation ◽

Convective Transport ◽

Convection Flow ◽

Local Similarity ◽

Mixed Convection Flow ◽

Local Skin ◽

Exponential Stretching

Micropolar boundary-layer flow and heat transfer characteristics associated with a heated exponential stretching continuous sheet being cooled by a mixed convection flow are examined. The relevant heat transfer mechanisms are of interest in a wide variety of practical applications such as hot rolling, continuous casting, extrusion, and drawing. The wall temperature and stretching velocity are assumed to vary according to specific exponential forms. The contributions of buoyancy along with viscous dissipation on the convective transport in the boundary-layer region is analyzed in the opposing and assisting flow situations. Local similarity solutions are obtained for the boundary-layer equations governing the problem. A parametric study of the mixed convection parameter ξ, the micropolar parameter Δ, the Eckert number Ec, the parameter of temperature distribution n, and Prandtl number Pr is conducted and a representative set of numerical results for the velocity, angular velocity, temperature profiles, local skin friction coefficient, wall couple stress parameter, and local Nusselt number are illustrated graphically to show typical trends of the solutions.

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