scholarly journals Thermal characteristics of longitudinal fin with Fourier and non-Fourier heat transfer by Fourier sine transforms

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Basma Souayeh ◽  
Kashif Ali Abro
Keyword(s):  
Heat Transfer ◽  
High Performance ◽  
Heat Dissipation ◽  
Special Functions ◽  
Thermal Characteristics ◽  
Hyperbolic Heat Conduction ◽  
Fourier Sine ◽  
Fractional Modeling ◽  
Transfer Equations ◽  
Mathematical Techniques

AbstractThe quest for high-performance of heat transfer components on the basis of accommodating shapes, smaller weights, lower costs and little volume has significantly diverted the industries for the enhancement of heat dissipation with variable thermal properties of fins. This manuscript proposes the fractional modeling of Fourier and non-Fourier heat transfer of longitudinal fin via non-singular fractional approach. The configuration of longitudinal fin in terms of one dimension is developed for the mathematical model of parabolic and hyperbolic heat transfer equations. By considering the Fourier and non-Fourier heat transfer from longitudinal fin, the mathematical techniques of Fourier sine and Laplace transforms have been invoked. An analytic approach is tackled for handling the governing equation through special functions for the fractionalized parabolic and hyperbolic heat transfer equations in longitudinal fin. For the sake of comparative analysis of parabolic verses hyperbolic heat conduction of fin temperature, we depicted the distinct graphical illustrations; for instance, 2-dimensional graph, bar chart, contour graphs, heat graph, 3-dimensional graphs and column graphs on for the variants of different rheological impacts of longitudinal fin.

Convective Cooling of Compact Electronic Devices via Liquid Metals with Low Melting Points

2021 ◽  
Author(s):  
Guilin Liu ◽  
Jing Liu
Keyword(s):  
Heat Transfer ◽  
Melting Point ◽  
Liquid Metal ◽  
High Performance ◽  
Flow Resistance ◽  
Heat Dissipation ◽  
Liquid Metals ◽  
Electronic Devices ◽  
Convective Cooling ◽  
Heat Exchanger Design

Abstract The increasingly high power density of today's electronic devices requires the cooling techniques to produce highly effective heat dissipation performance with as little sacrifice as possible to the system compactness. Among the currently available thermal management schemes, the convective liquid metal cooling provides considerably high performance due to their unique thermal properties. This paper firstly reviews the studies on convective cooling using low-melting-point metals published in the past few decades. A group of equations for the thermophysical properties of In-Ga-Sn eutectic alloy is then documented by rigorous literature examination, following by a section of correlations for the heat transfer and flow resistance calculation to partially facilitate the designing work at the current stage. The urgent need to investigate the heat transfer and flow resistance of forced convection of low-melting-point metals in small/mini-channels, typical in compact electronic devices, is carefully argued. Some special aspects pertaining to the practical application of this cooling technique, including the entrance effect, mixed convection, and compact liquid metal heat exchanger design, are also discussed. Finally, future challenges and prospects are outlined.

An Improved Geometric Model to Predict Hot Spots of Castings

2011 ◽  
Vol 689 ◽  
pp. 29-32 ◽  
Author(s):  
Yan Xu ◽  
Kai Zhang ◽  
Hong Liang Zheng ◽  
Yu Cheng Sun ◽  
Xue Lei Tian
Keyword(s):  
Heat Transfer ◽  
Hot Spots ◽  
Heat Dissipation ◽  
Hot Spot ◽  
Geometric Model ◽  
Solidification Process ◽  
Dissipation Potential ◽  
Solidification Sequence ◽  
Transfer Equations ◽  
Riser Design

It is very important to predict the hot spots of castings properly, which is known as a criterion for riser design. In this paper, an improved geometric model for hot spot prediction is proposed, and subsequently, its application to hot spot analysis is presented. As we know, the heat dissipation potential of a location in a casting depends on its distance to the heat transfer surfaces. In a meshed casting, the reciprocal of distance from a certain cell to surfaces is calculated at all the six orthogonal directions, by which the heat dissipation potentials of every cell will be evaluated considering the influences of the neighboring grids. With the improved geometric model, there is no iteration during calculation, and only twice of cell traverse is required. The first traverse gets the distance reciprocal and the second focuses on the heat dissipation potential. The result of this model, which turns out similar to that of procedures based on heat transfer equations, reflects solidification sequence in a casting, hence the hot spots will be known instantaneously. Obviously this geometric model ignores many conditions during solidification process. However, messages like locations of hot spots are shown much faster and more conveniently than that of procedures based on heat transfer equations. Therefore, it is believed that it will shorten much time for casting technology design.

Numerical Investigation of Heat Transfer and Pressure Loss of Double-Layer Microchannels for Chip Liquid Cooling

2012 ◽  
Author(s):  
Gongnan Xie ◽  
Yanquan Liu ◽  
Bengt Sunden ◽  
Weihong Zhang ◽  
Jun Zhao
Keyword(s):  
Heat Transfer ◽  
Double Layer ◽  
Pressure Loss ◽  
Heat Dissipation ◽  
Thermal Characteristics ◽  
Parallel Flow ◽  
Air Cooling ◽  
Pumping Power ◽  
Liquid Cooling ◽  
Counter Flow

The problem involved in the increase of the chip output power of high-performance integrated electronic devices is the failure of reliability because of excessive thermal loads. This requires advanced cooling methods to manage the increase of the dissipated heat. The traditional air-cooling may not meet the requirements, and therefore a new generation of liquid cooling technology becomes necessary. Various microchannels are widely used to cool the electronic chips by a gas or liquid, but these microchannels are often designed to be single-layer channels. In this paper, the laminar heat transfer and pressure loss in a kind of double-layer microchannel have been investigated numerically. The layouts of parallel-flow and counter-flow for inlet/outlet flow directions are designed and then several sets of inlet flowrates are considered. The simulations show that such a double-layer microchannel can not only reduce the pressure drop effectively but also exhibits better thermal characteristics, and the parallel-flow layout is found to be better for heat dissipation when the pumping power is limited, while the counter-flow layout is better when a high pumping power is provided.

Fin Analysis Under Transition Boiling Heat Transfer: Part II — Radial Fins

2002 ◽  
Author(s):  
Rizos N. Krikkis ◽  
Stratis V. Sotirchos ◽  
Panagiotis Razelos
Keyword(s):  
Heat Transfer ◽  
Power Law ◽  
Biot Number ◽  
Boiling Heat Transfer ◽  
Heat Dissipation ◽  
Thermal Characteristics ◽  
Radius Ratio ◽  
Operating Variables ◽  
Simplifying Assumptions ◽  
Saturated Boiling

The thermal characteristics of six profiles of radial fins subject to transition boiling heat transfer are analyzed. The profiles considered are the rectangular the trapezoidal, the triangular, the convex parabolic, the parabolic and the hyperbolic. The model of the physical mechanism is based on one-dimensional heat conduction using certain simplifying assumptions while the heat transfer coefficient is modeled as a power-law function of the temperature difference between the fin and the saturated boiling liquid with a negative exponent. The problem is formulated by means of dimensionless variables and parameters such as the conduction-convection parameter, the radius ratio and the Biot number that characterize the problem. The multiplicity structure is obtained in order to determine the different types of bifurcation diagrams, which describe the dependence of a state variable of the system (for instance the fin temperature or the heat dissipation) on a design (CCP, radius ratio) or operation parameter (power-law exponent). Specifically the effects of the radius ratio, of the CCP and of the Biot number are analyzed and presented in several diagrams since it is important to know the behavioral features of the heat rejection mechanism such as the number of the possible steady states and the influence of a change in one or more operating variables to these states.

Compact Transient Thermal Model of Microfluidically Cooled Three-Dimensional Stacked Chips With Pin-Fin Enhanced Microgap

2021 ◽  
Vol 143 (3) ◽  
Author(s):  
Yuanchen Hu ◽  
Md Obaidul Hossen ◽  
Zhimin Wan ◽  
Muhannad S. Bakir ◽  
Yogendra Joshi
Keyword(s):  
Heat Transfer ◽  
Integrated Circuit ◽  
High Performance ◽  
Heat Dissipation ◽  
Three Dimensional ◽  
Heat Removal ◽  
Power Estimation ◽  
Leakage Power ◽  
Pin Fin ◽  
Pin Fins

Abstract Three-dimensional (3D) stacked integrated circuit (SIC) chips are one of the most promising technologies to achieve compact, high-performance, and energy-efficient architectures. However, they face a heat dissipation bottleneck due to the increased volumetric heat generation and reduced surface area. Previous work demonstrated that pin-fin enhanced microgap cooling, which provides fluidic cooling between layers could potentially address the heat dissipation challenge. In this paper, a compact multitier pin-fin single-phase liquid cooling model has been established for both steady-state and transient conditions. The model considers heat transfer between layers via pin-fins, as well as the convective heat removal in each tier. Spatially and temporally varying heat flux distribution, or power map, in each tier can be modeled. The cooling fluid can have different pumping power and directions for each tier. The model predictions are compared with detailed simulations using computational fluid dynamics/heat transfer (CFD/HT). The compact model is found to run 120–600 times faster than the CFD/HT model, while providing acceptable accuracy. Actual leakage power estimation is performed in this codesign model, which is an important contribution for codesign of 3D-SICs. For the simulated cases, temperatures could decrease 3% when leakage power estimation is adopted. This model could be used as electrical-thermal codesign tool to optimize thermal management and reduce leakage power.

Experimental Investigation on Flow and Thermal Characteristics of a Micro Phase-Change Cooling System With a Microgroove Evaporator

2006 ◽  
Author(s):  
Xuegong Hu ◽  
Dawei Tang
Keyword(s):  
Heat Transfer ◽  
Thermal Resistance ◽  
Heat Dissipation ◽  
Cooling System ◽  
Thermal Sensitivity ◽  
Thermal Characteristics ◽  
Cooling Capacity ◽  
Input Power ◽  
Maximum Heat ◽  
Transportation Capacity

In this paper, a natural convection micro cooling system with a capillary microgroove evaporator is proposed. An experimental study on the characteristics of thermal resistance, pressure drop and heat transfer of the cooling system was carried out. Experimental results indicate that the liquid fill ratio has a significant influence on thermal resistance and heat transfer in the cooling system. Increasing system’s cooling capacity at higher input power depends on decreasing the thermal resistance between the outer surfaces of the condenser and ambient environment. Compared with a flat miniature heat pipe (FMHP) and a current fan-cooled radiator for CPU chip of Pentium IV, the present micro cooling system has a stronger heat dissipation capacity. Its best cooling performance at a surface temperature of heat source below 373K reaches 1.68×106W/m2 and the maximum heat transportation capacity is 131.8W. The novel kind of cooling system is suitable for remote cooling of those electronic parts with micro size, high power and thermal sensitivity.

A Method to Estimate Real-Time Energy Performance and Carbon Offsets in Residential Buildings

2010 ◽  
Author(s):  
Sergio Escobar ◽  
Jorge E. Gonza´lez ◽  
Adam Wong ◽  
Mark Aschheim
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Real Time ◽  
High Performance ◽  
Residential Buildings ◽  
Thermal Characteristics ◽  
Energy Performance ◽  
Carbon Offsets ◽  
Overall Heat Transfer Coefficient

A method is presented to determine energy performance of residential buildings. The method is based on an extended application of the degree-days basis to determine building thermal performance. The overall heat transfer coefficient and radiation shading factors are extracted from nightime and daytime readings of indoor and outdoor temperatures, solar radiation, and total energy usage of the building. It is shown that the overall heat transfer coefficient (thermal response) UA of the building is linear. Radiation shading factors can be represented as nonlinear functions of time. Application of the method to estimate real-time energy performance and carbon offsets of high performance buildings is discussed. The performance of the building is compared with an equivalent building with standard physical and thermal characteristics.

Enhancement of Hard Disk Drive Heat Dissipations With Integrated Cooling Devices

2008 ◽  
Author(s):  
J. P. Yang ◽  
C. P. H. Tan ◽  
E. H. Ong
Keyword(s):  
Power Consumption ◽  
High Performance ◽  
Heat Dissipation ◽  
Hard Disk Drives ◽  
Thermal Characteristics ◽  
Hard Disk ◽  
Disk Drive ◽  
Disk Drives ◽  
Design Engineers ◽  
Operational Life

Thermal management has become a significant issue to be considered whilst designing high performance and high reliable hard disk drives (HDD). This paper proposes a compact ultra-thin cooling device for enhancing heat dissipation of HDD. The miniature device was designed and prototyped to its optimal cooling efficiency according to the thermal characteristics of operating HDD. The experimental results of this newly developed device show that it can offer up to 35% enhancement of heat dissipation with a lower power consumption of 10 mW. Furthermore, the low power consumption device has been fully integrated with the disk drive without modifying the structure of the disk drive. This device provides a key for the design engineers in developing reliable and longer operational life hard disk drives.

scholarly journals EDITORIAL

2016 ◽  
Vol 15 (2) ◽  
pp. 02
Author(s):  
Sam Yang
Keyword(s):  
Heat Transfer ◽  
High Performance ◽  
Heat Dissipation ◽  
Complex Geometry ◽  
Scientific Progress ◽  
Thermal Engineering ◽  
Future Research ◽  
Minimum Entropy ◽  
Maximum Heat ◽  
Maximum Heat Transfer

The editorial of Engenharia Térmica of this issue continues the discussion on scientific research needs in vital areas in which thermal engineering has important participation. The main goal is to motivate the readers, within their specialties, to identify possible subjects for their future research. Extensive research efforts have been devoted to the development of high performance heat sinks, and numerous geometric designs and fin arrangements as well as materials have been proposed to achieve higher heat dissipation rates. Previous studies have deduced different fin geometries and arrangements based on minimum entropy generation or maximum heat transfer rate, subject to various constraints such as available space, material, or cost. Consequently, many fin shapes and arrangements exist in literature ranging from elliptical cylinders to rhombus, and from pin to flared fin, respectively. According to the literature review, however, helical fins have not yet been explored as an alternative design owing to its complex geometry that restricts the analysis to 3D space. Therefore, a 3D helical fin model still needs to be developed to investigate its feasibility and performance as an alternative fin design. In addition, a helical fin arrangements optimization study shall be conducted for minimum pressure drop and maximum heat transfer. The mission of Engenharia Térmica is to document the scientific progress in areas related to thermal engineering (e.g., energy, oil and renewable fuels). We are confident that we will continue to receive articles’ submissions that contribute to the progress of science.

CFD Analysis on Liquid Cooled Cold Plate Using Copper Nanoparticles

2020 ◽  
Author(s):  
Pardeep Shahi ◽  
Sarthak Agarwal ◽  
Satyam Saini ◽  
Amirreza Niazmand ◽  
Pratik Bansode ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Copper Nanoparticles ◽  
High Performance ◽  
Data Centers ◽  
Heat Dissipation ◽  
Great Promise ◽  
Thermal Mass ◽  
Air Cooling ◽  
Cold Plate ◽  
Cfd Analysis

Abstract In today’s world, most data centers have multiple racks with numerous servers in each of them. The high amount of heat dissipation has become the largest server-level cooling problem for the data centers. The higher dissipation required, the higher is the total energy required to run the data center. Although still the most widely used cooling methodology, air cooling has reached its cooling capabilities especially for High-Performance Computing data centers. Liquid-cooled servers have several advantages over their air-cooled counterparts, primarily of which are high thermal mass, lower maintenance. Nano-fluids have been used in the past for improving the thermal efficiency of traditional dielectric coolants in the power electronics and automotive industry. Nanofluids have shown great promise in improving the convective heat transfer properties of the coolants due to a proven increase in thermal conductivity and specific heat capacity. The present research investigates the thermal enhancement of the performance of de-ionized water-based dielectric coolant with Copper nanoparticles for a higher heat transfer from the server cold plates. Detailed 3-D modeling of a commercial cold plate is completed and the CFD analysis is done in a commercially available CFD code ANSYS CFX. The obtained results compare the improvement in heat transfer due to improvement in coolant properties with data available in the literature.

Sign in / Sign up

Export Citation Format

Share Document