Fin Base Thickness Research Articles

PARTICLE SWARM OPTIMIZATION AND CFD ANALYSIS OF A HEAT SINK FOR FORCED CONVECTIVE COOLING OF A DC/AC INVERTER

Power inverters play a crucial role in converting DC voltage and current to AC voltage and current. Its efficient operation relies on effective thermal management of the semiconductor devices, such as the IRF 3205 MOSFET chip which facilitate the switching operations to prevent thermo-mechanical stress that could to failure. This research developed and optimize a heat sink for an IRF 3205 MOSFET chip in a 3.5 KVA power inverter, using the Particle Swarm Optimization technique and experimented with a 3.5 KVA 24 V power inverter operating a 1.5HP air-conditioning unit. The heat sink geometry has 26 fins, 4 mm fin thickness, 40 mm fin height, 3 mm fin spacing, 2 mm fin base thickness, 179 mm length, 80 mm width and a thermal resistance of 60.75 °C/W. The thermal performance was evaluated using ANSYS Computational Fluid Dynamics (CFD) and results showed maximum base temperature of 65.85°C and experimental temperature of 64°C after two hours of steady operation dissipating heat of 45W. The results from both numerical and experimental data demonstrate the effectiveness of the optimized heat sink in maintaining the chip's temperature below its maximum working threshold of 170°C.

Thermal management and fin characteristic optimization of an electronic power supply utilizing Taguchi and ANOVA methods

In the rapidly advancing field of electronic power supplies, managing thermal performance is critical. This study focuses on optimizing fin geometries to enhance the thermal management of an amplifier used in car multimedia systems, utilizing Taguchi and ANOVA methods for both thermal and volumetric efficiencies. Analyses were conducted on the impact of five distinct fin parameters—fin gap, fin thickness, separated plate thickness, fin base thickness, and fin height—on the system’s thermal behavior and the fin volume. Computational Fluid Dynamics (CFD) analyses were performed for 24 different configurations. These analyses showed significant potential for improvement in the original design, with optimizations leading to an 8.31% reduction in the amplifier temperature and a 51.91% reduction in the fin volume. The study identifies fin height as the most effective parameter on the amplifier temperature, with an effect rate of 57.26%, while fin base thickness showed the most significant effect on the fin volume, with an effect rate of 66.98%. These findings not only provide a basis for more efficient design but also offer predictive insights through formulated regression equations, thus reducing the dependency on extensive experimental setups.

Effect of micro-fin tube geometry parameters on evaporator material savings

A Performance Evaluation Criteria (PEC) analysis is presented that explores the influence of the micro-fin tube geometry on the required material volume. The analysis was done using a local flow boiling model, which can quantify the effect of fin parameters and the tube diameter. The PEC was done while requiring that the compared surfaces satisfy the same heat duty and pressure drop. The following tube parameters and ranges were explored: tube diameter (3 mm ≤ Do ≤ 6 mm), fin base thickness (0.12 mm ≤ tbf ≤ 0.29 mm), helix angle (6° ≤ α ≤ 30°), fin apex angle (11° ≤ β ≤ 22°), total number of fins (43 ≤ nf ≤ 70), and the fin height (0.11 mm ≤ e ≤ 0.3 mm). The tube that provided the smallest material requirements within the examined parameter ranges had: Do = 3 mm, tbf = 0.12 mm, α = 6°, β = 11°, nf = 43, and e = 0.3 mm. In general, small Do and tbf and large nf and e provided the best performance and work to minimize the required material volume to provide a given heat duty and pressure drop. The helix and the fin-tip apex angles were found to have very little influence on the performance for the examined range of parameters and angles associated with the lowest production cost should be chosen.

Thermal Management of Microelectronic Devices Using Nanofluid with Metal foam Heat Sink.

Microelectronic components are used in a variety of applications that range from processing units to smart devices. These components are prone to malfunctions at high temperatures exceeding 373 K in the form of heat dissipation. To resolve this issue, in microelectronic components, a cooling system is required. This issue can be better dealt with by using a combination of metal foam, heat sinks, and nanofluids. This study investigates the effect of using a rectangular-finned heat sink integrated with metal foam between the fins, and different water-based nanofluids as the working fluid for cooling purposes. A 3D numerical model of the metal foam with a BCC-unit cell structure is used. Various parameters are analyzed: temperature, pressure drop, overall heat transfer coefficient, Nusselt number, and flow rate. Fluid flows through the metal foam in a turbulent flow with a Reynold's number ranging from 2100 to 6500. The optimum fin height, thickness, spacing, and base thickness for the heat sink are analyzed, and for the metal foam, the material, porosity, and pore density are investigated. In addition, the volume fraction, nanoparticle material, and flow rate for the nanofluid is obtained. The results showed that the use of metal foam enhanced the thermal performance of the heat sink, and nanofluids provided better thermal management than pure water. For both cases, a higher Nusselt number, overall heat transfer coefficient, and better temperature reduction is achieved. CuO nanofluid and high-porosity low-pore-density metal foam provided the optimum results, namely a base temperature of 314 K, compared to 341 K, with a pressure drop of 130 Pa. A trade-off was achieved between the temperature reduction and pumping power, as higher concentrations of nanofluid provided better thermal management and resulted in a large pressure drop.

Analysis of a concave parabolic fin with vertically cutting fin tip and variable fin base thickness

A concave parabolic fin with vertically cutting fin tip and variable fin base thickness is analyzed using a two-dimensional analytic method. Heat loss is presented as a function of the actual fin length, the ratio of the actual fin length to the imaginary fin length, the fin base height, and the convection characteristic number. Also, heat loss is shown as a function of the fin base thickness for both the fixed actual fin length and the fixed actual fin tip length. For equal amounts of heat loss, the relationships are presented between 1) the convection characteristic number and the fin base height, 2) the fin base thickness and the fin base height, and 3) the fin base thickness and the actual fin tip length. One of the results shows that the heat loss for the fixed actual fin tip length decreases more remarkably than that for the fixed actual fin length as the fin base thickness increases.

Numerical analysis for thermo-hydraulic performance of staggered cross flow tube bank with longitudinal tapered fins

Cross flow tube bank is an important constituent in most of the industrial heat exchanging systems such as Heating Ventilation and Air Conditioning (HVAC) systems, Waste Heat Recovery systems and Industrial Boilers. Considering the depletion of fossil fuels and allied environmental concerns, there is a huge need for improving the performance of the cross flow tube bank. The present numerical study investigates the effect of longitudinal taper fins on external flow over staggered cross flow tube bank. The longitudinal fins of various length (0.50 ≤ L/D ≤ 1.50), base thickness (0.40 ≤ T/D ≤ 0.80) and end thickness (t/D = 0.12 and 0.28) are used to evaluate the thermal performance of the tube bank. The thermal hydraulic performance is evaluated considering the effects on rate of heat transfer along with pressure drop characteristics across the tube bank. The results shows that the use of longitudinal taper fins significantly enhances the thermal hydraulic performance of cross flow tube banks. Moreover, the increase in length of fin results in an appreciable enhancement in Nusselt number, which overrules the increase in pressure drop penalty. Whereas, the increase in the fin base thickness, results in a significant reduction in pressure drop capable of compensating the reduction in Nusselt number. Hence, increase in both these dimensions results in higher thermal hydraulic performance than the bare tube bank. On the other hand, fin end thickness plays only a minor role in the finned tube bank performance. Lowering the value of fin end thickness slightly increase the thermal performance by suppressing the friction factor.

Optimizing a Functionally Graded Metal-Matrix Heat Sink Through Growth of a Constructal Tree of Convective Fins

Optimal material utilization in metal-matrix heat sink is investigated using constructal design (CD) in combination with fin theory to develop a constructal tree of optimally shaped convective fins. The structure is developed through systematic growth of constructs, consisting initially of a single convective fin enveloped in a convective medium. Increasingly complex convective fin structures are created and optimized at each level of complexity to determine optimal fin shapes, aspect ratios, and fin-base thickness ratios. One result of the optimized structures is a functional grading of porosity. The porosity increases as a function of distance from the heated surface in a manner ranging from linear to a power function of distance with exponent of about 2. The degree of nonlinearity in this distribution varies depending on the volume of the heat sink and average packing density and approaches a parabolic shape for large volume. For small volume, porosity approaches a linear function of distance. Thus, a parabolic (or least-material) fin shape at each construct level would not necessarily be optimal. Significant improvements in total heat transfer, up to 55% for the cases considered in this work, were observed when the fin shape is part of the optimization in a constructal tree of convective fins. The results of this work will lead to better understanding of the role played by the porosity distribution in a metal-matrix heat sink and may be applied to the analysis, optimization, and design of more effective heat sinks for electronics cooling and related areas.

Analysis of Reversed Trapezoidal Fins using a 2-D Analytical Method

This paper presents a two-dimensional analysis of reversed trapezoidal fins with variable fin base thickness. Heat loss from the reversed trapezoidal fin is presented as a function of the fin shape factor, fin base thickness, and fin base height. The relationship between the fin tip length and the convection characteristic number, as well as that between the fin tip length and the fin base height for equal amounts of heat loss are analyzed. In addition, the relationship between the fin base thickness and the fin shape factor for equal amounts of heat loss is presented. One of the results shows that the heat loss decreases linearly with the increase in the fin shape factor.

Optimization of geometrically asymmetric straight trapezoidal fins

Geometrically asymmetric trapezoidal fins with variable slope of fin’s top surface are optimized for fixed fin volumes. Convection from the inside fluid to the inside wall, conduction from the inside wall to the fin base and conduction through the fin base are considered simultaneously for the fin base boundary condition. For fixed fin volumes, the optimum heat loss, the corresponding optimum fin length, and fin base height are presented as functions of the fin base thickness, inside fluid convection characteristic number, fin volume, fin shape factor, and ambient convection characteristic number. The optimum values between 1-D and 2-D analyses are compared. One of the results shows that both the optimum fin length and fin base height decrease with the increase of the fin shape factor.

고출력 LED 램프 용 방사형 히트싱크의 형상 및 표면코팅이 LED 냉각성능에 미치는 영향에 대한 연구

The purpose of this study is to investigate the cooling performance of radial heat sink used for high power LED lightings by natural convection cooling with surrounding air. Experimental and numerical analyses are carried out together. Parametric studies are performed to compare the effects of geometric parameters in radial heat sink such as the number of fins, fin height, fin length, and thickness of fin base as well as the surface coatings of radial heat sink. In this study, the cooling of 60 W LED lamp is examined with radiative heat transfer considered as well as natural convection. Numerical results show the optimum condition when the number of fin is 40, heat sink height is 120 mm, fin length is 15 mm, and fin base thickness is 3 mm. The difference in temperature of the LED metal PCB is within <TEX>$1^{\circ}C$</TEX> between numerical analyses and experimental results. Also, the CNT coating on the heat sink surface is found to increase the cooling performance significantly.

고정된 핀 바닥 높이에 기준한 비대칭 사다리꼴 핀의 최적화

위 측면 표면 기울기가 변화하는 비대칭 사다리꼴 핀의 최적화가 2차원 해석적 방법을 사용하여 수행된다. 고정된 핀 바닥 높이에 대하여 최적 열손실, 핀 길이 그리고 유용도가 내부유체 대류특성계수, 핀 바닥 두께, 핀 바닥 높이, 핀 형상계수 그리고 주위 대류특성계수의 함수로 나타내어진다. 이러한 최적화 절차를 위해서 핀으로부터의 최대 열손실 값의 95%를 최적 열손실 값으로 정의하였다. 결과 중 하나는 최적 열 손실과 유용도는 핀 형상계수의 변화에 독립적으로 보이는 반면 최적 핀 길이는 핀 형상계수가 증가함에 따라 거의 선형적으로 감소함을 보여주고 있다. Optimization of the asymmetric trapezoidal fin with various upper lateral surface slope is made using a two-dimensional analytic method. For the fixed fin base height, the optimum heat loss, fin length and effectiveness are represented as inner fluid convection characteristic number, fin base thickness, fin base height, fin shape factor and ambient convection characteristic number. For this optimum procedure, the optimum heat loss is defined as 95% of the maximum heat loss from the fin. One of the results shows that optimum heat loss and effectiveness seems independent of the fin shape factor while optimum fin length decreases almost linearly as the fin shape factor increases.

ANALYSIS OF A REVERSED TRAPEZOIDAL FIN USING A 2-D ANALYTIC METHOD

A reversed trapezoidal fin is analyzed using a two-dimensional analytical method. Heat loss from the reversed trapezoidal fin is presented as a function of the fin shape factor, fin base thickness and the fin base height. The relationship between the fin tip length and the convection characteristic number as well as that between the fin tip length and the fin base height for equal amounts of heat loss are analyzed. Also the relationship between the fin base thickness and the fin shape factor for equal amount of heat loss is presented. One of the results shows that the heat loss decreases linearly with the increase of the fin shape factor.

Optimization of a Pin Fin With Variable Base Thickness

A pin fin with variable fin base thickness is optimized using a two-dimensional analytic method. The values of the inner wall temperature and fin volume are given as constants. The fin base temperature varies with variation in the fin base thickness, fin outer radius, fin length, and convection characteristic number. Under these conditions, the optimum heat loss, the corresponding optimum fin effectiveness, fin length, and fin outer radius are presented as functions of the fin base thickness, fin volume, and convection characteristic number. One of the results shows that both the optimum heat loss and optimum fin length decrease linearly with increase in the fin base thickness.

Optimization of a rectangular profile annular fin based on fixed fin height

The optimum performance and fin length of a rectangular profile annular fin are presented using a variations separation method. For fixed fin height, the optimum fin length and efficiency are arbitrarily defined as those for which the heat loss is in the range between 90% and 99% of the maximum heat loss. The maximum heat loss, the maximum effectiveness, the minimum fin resistance, the optimum fin length and the optimum efficiency are presented as a function of the inside fluid convection characteristic number, fin base thickness, fin height and ambient convection characteristic number. One of the results shows that the optimum fin length decreases almost linearly with the increase of the fin base thickness.

최대 열손실에 대한 열손실 비에 기준한 Pin 핀의 최적화

A pin fin with variable fin base thickness is optimized based on the ratio of heat loss to the maximum heat loss using a two-dimensional analytic method. The temperature profile along the normalized radius position in the fin is presented. For fixed fin outer radius, the optimum heat loss, fin length and efficiency as a function of fin base thickness, outer radius, convection characteristic numbers ratio and ambient convection characteristic number are presented. One of the results shows that the effect of fin outer radius and ambient convection characteristic number on the optimum fin length is remarkable.

Optimization of a reversed trapezoidal fin using a 2-D analytic method

A reversed trapezoidal fin with variable fin base thickness is optimized based on the fixed fin volume by using a two-dimensional analytic method. The variation of temperature along the normalized Y position at the fin tip is presented. For fixed fin volumes, the maximum heat loss, the corresponding optimum fin effectiveness, fin base height and fin tip length as a function of the fin base thickness, fin shape factor and the fin volume are presented. One of the results shows that both the optimum heat loss and the optimum fin length increase with the increase of the value of fin shape factor.

The optimal dimensions of convective-radiating circular fins

The optimal dimensions of convective-radiating circular fins with variable profile, heat-transfer coefficient and thermal conductivity, as well as internal heat generation are obtained. A profile of the form y=(w/2) [1+(r o/r) n ] is studied, while variation of thermal conductivity is of the form k=k o[1+ɛ((T−T ∞)/ (T b−T ∞)) m ]. The heat-transfer coefficient is assumed to vary according to a power law with distance from the bore, expressed as h=K[(r−r o)/(r e−r o)]λ. The results for λ=0 to λ=1.9, and −0.4≤ɛ≤0.4, have been expressed by suitable dimensionless parameters. A correlation for the optimal dimensions of a constant and variable profile fins is presented in terms of reduced heat-transfer rate. It is found that a (quadratic) hyperbolic circular fin with n=2 gives an optimum performance. The effect of radiation on the fin performance is found to be considerable for fins operating at higher base temperatures, whereas the effect of variable thermal conductivity on the optimal dimensions is negligible for the variable profile fin. It is also observed, in general, that the optimal fin length and the optimal fin base thickness are greater when compared to constant fin thickness.

Practical Fin Shapes for Surface-Tension-Drained Condensation

This paper introduces a new family of high-performance fin profiles for surface-tension-drained condensation. Previously described profiles for this situation have been defined in terms of the fin curvature and arc length. The existing profiles are generally not suitable for commercial manufacture. The fin profiles presented in this paper are conveniently defined by the fin tip radius, the fin height, and the fin base thickness. Consequently, the designer may easily specify a fin shape with parameters that are compatible with those used by the manufacturing industry. The heat transfer performance of the new profiles provides an improvement over existing, commercial fin shapes. An analysis is presented to show the R-11 condensation performance of the new profiles as a function of the geometric variables. A recommended design practice for fins for surface-tension-drained condensation is given also.

Heat Transfer and Pressure Drop of Typical Air Cooler Finned Tubes

The heat transfer and pressure drop performance of heat exchangers fabricated from helically wrapped finned tubes with an equilateral triangular pitch arrangement are reported for one through five rows. Two finned tube types were tested, one with a “T” foot and the other with an overlapped “L” foot. The dimensions of both finned tubes were similar and were typical of those used in air-cooling applications. The tube diameter was 25.4 mm; the fin height was 15.87 mm; the fin number was 0.41/mm; and the fin-tip clearance was 6.35 mm. The fin base thickness was 0.38 mm and was tapered to half the base thickness at the fin outside diameter. No difference in the thermal performance of the two finned tube types could be detected. Both the heat transfer coefficient and pressure drop were found to increase with the number of tube rows. These results were then compared to other published data.