scholarly journals Entropy Analysis of Complete Condensation of Saturated Steam on a Vertical Wall Using Nusselt Velocity and Temperature Profile in a Condensate Layer

Author(s):  
Martina Rauch ◽  
Saša Mudrinić ◽  
Antun Galović
Entropy ◽  
2020 ◽  
Vol 22 (10) ◽  
pp. 1070 ◽  
Author(s):  
Lijun Zhang ◽  
Muhammad Mubashir Bhatti ◽  
Marin Marin ◽  
Khaled S. Mekheimer

The present analysis deals with the entropy analysis of the blood flow through an anisotropically tapered arteries under the suspension of magnetic Zinc-oxide (ZnO) nanoparticles (NPs). The Jeffrey fluid model is contemplated as blood that is electrically conducting and incompressible. The lubrication approach is used for the mathematical modeling. The second law of thermodynamics is used to examine the entropy generation. The exact solutions are obtained against velocity and temperature profile with the use of computational software. The results for Entropy, Velocity, Bejan number, temperature profile, and impedance profile are discussed by plotting the graphs. ZnO-NPs have promising applications in biomedical engineering due to its low toxicity, economically reliable, and excellent biocompatibility. ZnO-NPs also emerged in medicine i.e., antibacterial and anticancer activity, and also beneficial in antidiabetic treatment. The monitoring of the blood temperature in the case of the tapered artery has supreme importance in controlling the temperature of blood in the living environment. The presence of a magnetic field is advantageous to manage and control the blood motion at different temperatures. The present outcomes are enriched to give valuable information for the research scientists in the field biomedical science, who are looking to examine the blood flow with stenosis conditions and also beneficial in treating multiple diseases.


1982 ◽  
Vol 104 (1) ◽  
pp. 24-33 ◽  
Author(s):  
K. Taghavi-Tafreshi ◽  
V. K. Dhir

Melting of a vertical wall as a result of condensation of saturated vapor is investigated both analytically and experimentally. Employing similarity transformations, full boundary layer equations governing laminar films of melt and condensate are solved numerically for high Prandtl number liquids. Numerical results for the melting and condensation heat transfer and for the melt-condensate interface temperature are obtained. Experiments are conducted by condensing saturated steam on vertical surfaces of slabs made of naphthalene, biphenyl and stearic acid. The data are found to compare well with the predictions. The analysis is extended to condensation on melting surfaces with shapes yielding variable gravity in the direction of flow.


1983 ◽  
Vol 105 (2) ◽  
pp. 235-240 ◽  
Author(s):  
K. Taghavi-Tafreshi ◽  
V. K. Dhir

Condensation-driven melting of an initially vertical wall is studied both analytically and experimentally. It is shown that a vertical surface undergoing simultaneous melting-condensation will not stay vertical and will go through a series of transient shapes before attaining a steady-state shape. Numerical solutions are obtained both for the transient shapes of the wall and the heat transfer. The steady-state shape of the wall is found to be the one which yields a constant melting rate along the wall. The total melting rate is shown to increase during the time the shape change occurs such that the steady-state shape yields about 35 percent more melting rate than the initial vertical wall. Experiments are conducted at one atmosphere pressure by condensing saturated steam on vertical surfaces of slabs made of naphthalene, biphenyl, and stearic acid. The heat transfer and shape change data are found to compare well with the predictions.


2010 ◽  
Vol 26 (1) ◽  
pp. N1-N7 ◽  
Author(s):  
T.-B. Chang

AbstractThis paper presents an analytical investigation into the effect of vapor superheating on the mixed-convection of a condensate layer flowing along the outside surface of an isothermal vertical cylinder. The governing system of partial differential equations is transformed into a dimensionless form using the nonsimilar transformation method. In investigating the heat transfer characteristics within the condensate layer and vapor phase, the analysis takes account of both the inertia effects and the convection effects within the condensate layer and the shear resistance at the liquid-vapor interface. The numerical results reveal that vapor superheating has a negligible effect on the temperature profile and local Nusselt number within the condensate layer. Moreover, it is found that a higher forced-flow intensity increases the temperature gradient in the vapor phase, but has a marginal effect on the temperature profile in the condensate layer. Finally, it is shown that the velocity at the liquid-vapor interface increases as the intensity of the forced-flow increases or as the ratio of the condensate layer viscosity to the vapor phase viscosity reduces.


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