Optimal Design of Constructal T-Shaped Fin Under Partially Wet Condition for Enhanced Thermal Performance: An Analytical Approach

Abstract

In refrigeration and air conditioning systems, the fin surface may become dry, fully wet or partially wet depending upon the psychometric, thermo-physical and geometric parameters. The current work is intended to determine the length of the dry portion, temperature distribution, performance and optimum design parameters of a T-shaped fin under partially wet condition. Temperature dependent thermal conductivity of the fin material is taken and the humidity ratio of saturated air is considered to vary linearly with the corresponding fin surface temperature. Considering these the governing equation of T-shaped fin becomes nonlinear and it has been solved analytically by using Homotopy Perturbation Method. The point of separation between the dry and wet portions of a T-shaped fin may be located either in the stem or flange part and hence, two cases having different governing equations and boundary conditions are analyzed in the current study. For the optimization study, Lagrange multiplier technique is employed and the results are obtained by maximizing the heat transfer rate for a constant fin volume. Further, a comparative study is presented between insulated and convective fin tip conditions.     

In-Vitro Release Kinetics of Salbutamolsulphate Microcapsules Coated with Both Eudragit Rs 100 and Eudragit RL 100

Sabutamolsulphate, a bronchodialatory drug for Asthma is encapsulated by Eudragit RS 100 and Eudragit RL 100 of varying ratios (1:1, 3:1, 1:3) using Emulsion-Solvent-Evaporation method. The experimental data obtained from the in-vitro dissolution study have been computed in the light of different kinetic models like Zero Ordr, Higuchi Matrix, First Order, Baker-Lonsdale. An extensive programming in BASIC is performed to determine the co-relation coefficient and slope for each of the functions. The diffusivity rate constant (K_BL) and diffusion coefficient (Da) have been evaluated with the help of Baker-Lonsdale Model.     

Novel encryption technique for security enhancement in optical code division multiple access

Photonic Network Communications - In this paper, a novel two dimensional (2D) wavelength/time (W/T) optical code division multiple access (OCDMA) code with zero cross-correlation property to...     

A metaheuristic analysis of heat transfer rates through porous fins of tapered and step profiles: a comparative study

Neural Computing and Applications - The advanced high-end gadgets and sophisticated machines require effective mechanism of transferring heat away from the sources. In a large number of...     

Experimental design of tritium extraction loop from lead lithium eutectic

Effective tritium breeding achievable in Test Blanket Module (TBM) is a major issue for sustainable fusion energy program. Equally important is tritium extraction to recover and recycle tritium back to fusion reactor. Tritium extraction from lead lithium is much more complicated than from purge gas due to low tritium extraction efficiency in transfer step to gas phase and the limitations imposed on space and lead lithium inventory in port cell. Earlier investigations do suggest the preference of packed columns over bubble columns. Theoretical models based on axial dispersion plug flow in liquid and gas proposed for bubble columns and packed columns are reinvestigated for different boundary conditions.This paper highlights the critical issues of experimental design based on tritium extraction efficiency and its impact on recovery loop. Steady state closed loop for absorption and stripping of hydrogen isotopes using inert gas is designed along with the associated auxiliaries.     

Effect of nanofluid on thermo hydraulic performance of double layer tapered microchannel heat sink used for electronic chip cooling

Thermo-hydraulic performance analysis of a tapered double layer microchannel heat sink (DL-MCHS) is done numerically. Water and Al₂O₃–H₂O nanofluid coolants are used with uniform heat flux at the base of DL-MCHS. Comparatively higher heat transfer and lower pressure drop can be achieved considering temperature dependent thermo-physical properties. An overall performance factor is determined which indicates that though the tapered channel gives better thermal performance than straight channel, it is not always advantageous, if hydraulic performance is also considered, due to the increase in pressure drop penalty. Finally, from optimization study, maximum heat transfer is obtained at tapering factor of 0.32.     

Thermal analysis of a constructal T-shaped porous fin with simultaneous heat and mass transfer

The present work establishes an analytical model for computing the temperature distribution,fin efficiency and optimum design parameters of a constructal T-shaped porous fin operating in fully wet condition.For more practical results,this study considers a cubic polynomial relationship between the humidity ratio of saturated air and the corresponding fin surface temperature.The temperature distribution has been determined by solving the highly non-linear governing equations using a semi-analytical transformation technique called Differential Transform Method.A comparison of the results with that of a numerical model shows that this transformation method is a very efficient and convenient tool for solution of non-linear problems.The effects of various geometric,thermo-physical and psychometric parameters on the temperature distribution,fin efficiency and optimum design condition have been investigated.Also,a comparison has been presented between solid and porous fins and the results point out that by selecting an appropriate value of porosity,the heat transfer rate can be increased than the corresponding solid fin.     

Experimental and numerical investigation of square heat sink having staggered and inline pin fin arrays placed at different orientation

Journal of Mechanical Science and Technology - The present problem is devoted to establish the effect of orientation on thermohydraulic performance of a horizontal heat sink with vertical...     

A model on the basis of analytics for computing maximum heat transfer in porous fins

This study presents an analytical work on the performance and optimum design analysis of porous fin of various profiles operating in convection environment. Straight fins of four different profiles, namely, rectangular, convex parabolic and two exponential types are considered for the present investigation. An analytical technique based on the Adomian decomposition method is proposed for the solution methodology as the governing energy equations of porous fins for all the profiles are non-linear. A comparative study has been carried out among the results obtained from the porous and solid fins, and an appreciable difference has been noticed for a range of design conditions. Finally, the result shows that the heat transfer rate in an exponential profile with negative power factor is much higher than the rectangular profile but slightly higher than the convex profile. On the other hand, the fin performance is observed to be better for exponential profiles with positive power factor than other three profiles. A significant increase in heat transfer through porous fins occurs for any geometric fin compared to that of solid fins for a low porosity and high flow parameter.