scholarly journals Numerical optimization of louvered fin heat exchanger with variable louver angles

2012 ◽  
Vol 395 ◽  
pp. 012054 ◽  
Author(s):  
B Ameel ◽  
J Degroote ◽  
H Huisseune ◽  
P De Jaeger ◽  
J Vierendeels ◽  
...  
Author(s):  
Abdulkerim Okbaz ◽  
Ali Pınarbaşı ◽  
Ali Bahadır Olcay

In the present study, 3-D numerical simulations on heat and fluid flow characteristics of double-row multi-louvered fins heat exchanger are carried out. The heat transfer improvement and the corresponding pressure drop amounts were investigated depending on louver angles in the range of 20° ≤θ≤ 30°, louver pitches of Lp = 2,7mm, 3,5mm and 3,8mm and frontal velocities of Uin between 1.22 m/s and 3 m/s. The results are reported in terms of Colburn j-factor, Fanning friction factor f and area goodness factor j/f based on louver angle, louver pitch and Reynolds number. To understand local behavior of flow around louvered fins and heat exchanger tubes, flow visualization results of velocity vectors and stream-lines with temperature counters are presented. It is investigated that increasing louver angle enhances convective heat transfer while hydraulic performance decreases due to increased pressure drop. The flow noticeably behaves louver directed for all louver angles The flow can easily travel between different fins. This case study has been done to design and manufacture an industrial louver fin heat exchanger.


Author(s):  
Samsul Islam ◽  
Md. Shariful Islam ◽  
Mohammad Zoynal Abedin

The heat transfer enhancement is recycled in many engineering uses such as heat exchangers, refrigeration and air conditioning structures, chemical apparatuses, and automobile radiators. Hence many enhancing extended fin patterns are developed and used. In multi louvered fin, in this segment for multi-row fin and tube heat exchanger, an increase in heat transfer enhancement is found 58% for ReH = 350. When the Reynolds number is 1075, the temperature gradient is more distinct for greater louver angle that is the higher heat transfer enhanced for large louver angle. For variable louver angle heat exchanger, the maximum heat transfer improvement achieved by 118% Reynolds number at 1075. In the vortex generator for the delta winglet vortex generator, the extreme enhancement of heat transfer increased to 16% compared to the baseline geometry (at ReDh = 600). For a compact louvered heat exchanger, the results showed that a regular arrangement of louvered fins gives a 9.3% heat transfer improvement. In multi-region louver fins and flat tubes heat exchanger, the louver fin with 4 regions and the louver fin with 6 regions are far better than the conventional fin in overall performance. At the same time, the louver fin with 6 regions is also better than the louver fin with 4-region. The available work is in experimental form as well as numerical form performed by computational fluid dynamics.


2020 ◽  
Author(s):  
Harpreet Kaur Aasi ◽  
Manish Mishra

Abstract Three-fluid compact heat exchanger of plate-fin type with parallel-flow configuration is optimised for the entropy generation. Four different types of plate fins (plain rectangular, offset strip, corrugated louvered and wavy fin) are embodied within heat exchanger for both co-current and counter-current flow arrangements have been selected for the study. Genetic algorithm is selected as an optimisation tool having apt in handling various continuous variables and discrete variables and the problems with complexities in the objective function as well as in constraints. Validation of the optimization model is carried out by comparing the results with that from experimental results, Particle swarm optimization (without heat duty constraint) and from graphical method (with heat duty constraint). It is observed that for a specified heat duty and given operating conditions corrugated louvered fin with counter-current flow arrangement offers the minimum entropy generation amongst all.


Author(s):  
M. Sabari ◽  
D. Channankiah ◽  
D. Shivalingappa

Heat exchanger plays a major role in almost all mechanical industries. Enhancement of heat transfer surface plays major role in numerous applications such as in heat exchangers, refrigeration and air conditioning systems etc. This paper examines the fluid flow and heat exchange on the air side of a multi-row fin-and-tube heat exchanger. A brief comparison is given between fin-and-tube heat exchanger attributes with louvered fins in a wider range of operating conditions defined by inlet air velocities. The brief representation on the calculated data for the louvered heat exchanger shows better heat transfer characteristics with a slightly higher pressure drop. The CFD procedure is validated by comparing the numerical simulation results with different inlet air velocities. Best combination of higher heat transfer and minimum pressure drop are occurred in inlet air velocity of 2.5 m/s.


Author(s):  
Sunil Mehendale

Microchannel evaporators are being increasingly considered for application in residential and commercial cooling and heat pump applications. This work analyzes the principles of refrigerant circuiting design in refrigerant-to-air heat exchangers using an element-by-element model developed for a microchannel evaporator. Geometric parameters such as microchannel tube depth, tube height, and port size, louvered fin density, louver angle, louver height, louver pitch, and fin height, as well as the air side face velocity, the refrigerant pressure-drop and heat transfer as a function of refrigerant mass flux are considered in the analysis. The model was first validated using data available in the open literature, thus providing a high level of confidence in the predictive ability of the model. Starting with a given microchannel tube and louvered fin geometry and a fixed number of tubes (and fins), the thermal performance of the heat exchanger was simulated over a wide range of two pass circuit configurations and tube lengths. It was found that the heat transfer versus pressure-drop trade-off provides an optimum relationship between the fraction of tubes in the first pass and the heat exchanger length. The sensitivity of the evaporator cooling capacity to the percentage of tubes in the first pass was also explored.


Author(s):  
Maria Pascu ◽  
Naser Sahiti ◽  
Franz Durst

The main objective of the present work was the derivation of heat transfer and pressure drop characteristics for pin fins which could be applied in heat exchangers used in the automobile industry. For this, 34 models of pin fin heat exchangers, characterized by a pin diameter of 0.35 mm, with both inline and staggered arrangements, were numerically investigated. The numerical results were validated through various comparison and validation procedures. The best performing pin fin configuration was determined by employing the performance plot: heat transfer per unit volume (or per unit area, if the pin height is constant) versus the energy input reduced to the same parameter as the heat transfer (volume or area). The heat exchanger performance plot showed that, for the investigated flow length, the staggered pin fin configuration performs better when compared to the inline arrangement. In order to prove the industrial applicability of these results, a louvered fin heat exchanger, commonly used as a car radiator, was experimentally investigated. A comparison of the best performing pin fin heat exchanger with the louvered fin model revealed an enhancement in the heat transfer of the pin fin model of 35%.


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