scholarly journals Leaf Vein-Inspired Bionic Design Method for Heat Exchanger Infilled with Graded Lattice Structure

Aerospace ◽  
2021 ◽  
Vol 8 (9) ◽  
pp. 237
Author(s):  
Haoyu Deng ◽  
Junpeng Zhao ◽  
Chunjie Wang
Keyword(s):  
Heat Exchanger ◽  
Heat Dissipation ◽  
Lattice Structure ◽  
Design Method ◽  
Mapping Method ◽  
Structure Design ◽  
Bionic Design ◽  
Leaf Vein ◽  
Transient Thermal ◽  
Graded Lattice

Due to its excellent performance and high design freedom, the lattice structure has shown excellent capabilities and considerable potential in aerospace and other fields. This paper proposes a method to map the biometric model to the lattice structure. Taking leaf veins as bionic objects, they are used to generate a bionic design with a gradient lattice structure to improve the performance of a heat exchanger. In order to achieve the above goals, this article also proposes a leaf vein model and a mapping method that combine the leaf vein model with the lattice structure. A series of transient thermal finite element simulations was conducted to evaluate and compare the heat dissipation performance of different designs. The analysis results show that the combination of the bionic design and the lattice structure effectively improves the heat dissipation performance of the lattice structure heat exchanger. The results indicate that the application of bionic design in lattice structure design has feasibility and predictable potential.

Stress Field Guided Lattice Structure Design Based on Hexahedral Mesh

2019 ◽  
Author(s):  
Lingyun Liu ◽  
Yizhou Liao ◽  
Shuming Gao
Keyword(s):  
Stress Field ◽  
Lattice Structure ◽  
Design Method ◽  
Structure Design ◽  
Complex Structures ◽  
Hexahedral Mesh ◽  
Principal Stress Direction ◽  
Lattice Design ◽  
Solid Models ◽  
Wide Range

Abstract Lattice structures are promising for a wide range of applications. The development of additive manufacturing (AM) technology has made it possible to manufacture complex structures. However, designing the optimal lattices of complex solid models efficiently and automatically remains a challenge. Thus, we propose a novel stress-field-guided lattice design method to improve the mechanical properties of a lattice structure. Stress field is used to make the boundary struts of each cell of a lattice structure aligning to the principal stress direction while remaining conformal. Hierarchical cell templates are designed to reduce the computational burden of the cell optimization of a lattice structure. The proposed method is verified experimentally, and the experimental results prove the efficiency and validity of the proposed method.

Overhang Support Structure Design for Electron Beam Additive Manufacturing

2017 ◽  
Author(s):  
Bo Cheng ◽  
Y. Kevin Chou
Keyword(s):  
Electron Beam ◽  
Additive Manufacturing ◽  
Design Process ◽  
Heat Dissipation ◽  
Design Method ◽  
Solid Substrate ◽  
Structure Design ◽  
Process Time ◽  
Support Structure ◽  
Powder Bed

Overhang structures are commonly found in Powder-bed metal additive manufacturing (AM) such as electron beam additive manufacturing (EBAM) process. The EBAM is assumed to build overhang structure without support features since powder bed could provide support. However, heat dissipation difference by sintered powder and solid substrate for overhang feature actually causes severe part distortion and requires support structure. Current support generation methods usually used certain types of structure to cover the overhang space. They may overestimate the support volume or put a large amount of supports, which could not be necessary and increase the post process time. Thus, the object of this task is to enhance the performance and efficient usage of the EBAM technology through effective support structure designs. In this study, a combined heat support and support anchor design method has been proposed. Numerical model has been used to evaluate stress and deformation during the design process. The detailed design process has been presented for a typical overhang and the simulation results have indicated that overhang deformation can be greatly reduced using this new method.

Thermal Management of Outdoor Electronic Cabinets Using Soil Heat Exchangers

2002 ◽  
Vol 124 (1) ◽  
pp. 7-11 ◽  
Author(s):  
Hisham E. Hegab ◽  
Eric B. Zimmerman ◽  
Gene T. Colwell
Keyword(s):  
Heat Exchanger ◽  
Heat Exchangers ◽  
Heat Dissipation ◽  
Element Model ◽  
System Level ◽  
Telephone Companies ◽  
Innovative Methods ◽  
Temperature Trends ◽  
Transient Thermal ◽  
Power Densities

Telephone companies utilize densely packed electronics in outdoor metal cabinets for routing calls between customers. As a result of the increasing power densities of electronics, companies are looking for innovative methods of providing system level cooling such as using soil heat exchangers. Numerical simulation using a system of lumped thermal capacitances coupled to a soil finite element model is used to predict the transient thermal behavior of a cabinet. The cabinet model has been verified in previous studies by comparison with experimental measurements on a commercial telecommunications cabinet and is shown to predict temperature trends well. The effects of transient heat load, soil properties, and heat exchanger geometry are examined. Results reveal soil heat exchangers have the capability to provide the necessary cooling for relatively low power outdoor cabinets. However, the temperature of the soil surrounding the heat exchanger may increase daily if the number and spacing of pipes is not adequate to handle the desired heat dissipation load.

scholarly journals Multi-Branch Cable Harness Layout Design Based on Genetic Algorithm with Probabilistic Roadmap Method

2021 ◽  
Vol 34 (1) ◽  
Author(s):  
Yingfeng Zhao ◽  
Jianhua Liu ◽  
Jiangtao Ma ◽  
Linlin Wu
Keyword(s):  
Genetic Algorithm ◽  
Topological Structure ◽  
Design Method ◽  
Route Planning ◽  
Layout Design ◽  
Structure Design ◽  
Prototype System ◽  
Cable Harness ◽  
Probabilistic Roadmap ◽  
Probabilistic Roadmap Method

AbstractCurrent studies on cable harness layouts have mainly focused on cable harness route planning. However, the topological structure of a cable harness is also extremely complex, and the branch structure of the cable harness can affect the route of the cable harness layout. The topological structure design of the cable harness is a key to such a layout. In this paper, a novel multi-branch cable harness layout design method is presented, which unites the probabilistic roadmap method (PRM) and the genetic algorithm. First, the engineering constraints of the cable harness layout are presented. An obstacle-based PRM used to construct non-interference and near to the surface roadmap is then described. In addition, a new genetic algorithm is proposed, and the algorithm structure of which is redesigned. In addition, the operation probability formula related to fitness is proposed to promote the efficiency of the branch structure design of the cable harness. A prototype system of a cable harness layout design was developed based on the method described in this study, and the method is applied to two scenarios to verify that a quality cable harness layout can be efficiently obtained using the proposed method. In summary, the cable harness layout design method described in this study can be used to quickly design a reasonable topological structure of a cable harness and to search for the corresponding routes of such a harness.

Design of Cooling Towers by the Effectiveness-NTU Method

1989 ◽  
Vol 111 (4) ◽  
pp. 837-843 ◽  
Author(s):  
H. Jaber ◽  
R. L. Webb
Keyword(s):  
Heat Exchanger ◽  
Cooling Tower ◽  
Design Method ◽  
Design Methods ◽  
Parallel Flow ◽  
Basic Method ◽  
Cooling Towers ◽  
Flow Configuration ◽  
Heat Exchanger Design

This paper develops the effectiveness-NTU design method for cooling towers. The definitions for effectiveness and NTU are totally consistent with the fundamental definitions used in heat exchanger design. Sample calculations are presented for counter and crossflow cooling towers. Using the proper definitions, a person competent in heat exchanger design can easily use the same basic method to design a cooling tower of counter, cross, or parallel flow configuration. The problems associated with the curvature of the saturated air enthalpy line are also treated. A “one-increment” design ignores the effect of this curvature. Increased precision can be obtained by dividing the cooling range into two or more increments. The standard effectiveness-NTU method is then used for each of the increments. Calculations are presented to define the error associated with different numbers of increments. This defines the number of increments required to attain a desired degree of precision. The authors also summarize the LMED method introduced by Berman, and show that this is totally consistent with the effectiveness-NTU method. Hence, using proper and consistent terms, heat exchanger designers are shown how to use either the standard LMED or effectiveness-NTU design methods to design cooling towers.

scholarly journals Thermal Analysis of Heat Distribution in Busbars during Rated Current Flow in Low-Voltage Industrial Switchgear

Energies ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2427
Author(s):  
Michał Szulborski ◽  
Sebastian Łapczyński ◽  
Łukasz Kolimas
Keyword(s):  
Structural Changes ◽  
Heat Dissipation ◽  
Current Flow ◽  
Low Voltage ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Coupled Analysis ◽  
Precise Representation ◽  
Transient Thermal ◽  
Halogen Free

The manuscript presents advanced coupled analysis: Maxwell 3D, Transient Thermal and Fluent CFD, at the time of a rated current occurring on the main busbars in the low-voltage switchgear. The simulations were procured in order to aid the design process of such enclosures. The analysis presented the rated current flow in the switchgear busbars, which allowed determining their temperature values. The main assumption of the simulation was measurements of temperature rise during rated current conditions. Simulating such conditions is a valuable asset in order to design better solutions for energy distribution gear. The simulation model was a precise representation of the actual prototype of the switchgear. Simulations results were validated by experimental research. The heat dissipation in busbars and switchgear housing through air convection was presented. The temperature distribution for the insulators in the rail bridge made of fireproof material was considered: halogen-free polyester. The results obtained during the simulation allowed for a detailed analysis of switchgear design and proper conclusions in practical and theoretical aspects. That helped in introducing structural changes in the prepared prototype of the switchgear at the design and construction stages. Deep analysis of the simulation results allowed for the development concerning the final prototype of the switchgear, which could be subjected to the full type tests. Additionally, short-circuit current simulations were procured and presented.

Calculation and Design Method Study of the Coil-Wound Heat Exchanger

2014 ◽  
Vol 1008-1009 ◽  
pp. 850-860 ◽  
Author(s):  
Zhou Wei Zhang ◽  
Jia Xing Xue ◽  
Ya Hong Wang
Keyword(s):  
Heat Transfer ◽  
Numerical Simulation ◽  
Heat Exchanger ◽  
Design Method ◽  
Fluid Velocity ◽  
Exchange Process ◽  
Three Dimensional ◽  
Simulation Method ◽  
Physical Parameters ◽  
Numerical Result

A calculation method for counter-current type coil-wound heat exchanger is presented for heat exchange process. The numerical simulation method is applied to determine the basic physical parameters of wound bundles. By controlling the inlet fluid velocity varying in coil-wound heat exchanger to program and calculate the iterative process. The calculation data is analyzed by comparison of numerical result and the unit three dimensional pipe bundle model was built. Studies show that the introduction of numerical simulation can simplify the pipe winding process and accelerate the calculation and design of overall configuration in coil-wound heat exchanger. This method can be applied to the physical modeling and heat transfer calculation of pipe bundles in coil wound heat exchanger, program to calculate the complex heat transfer changing with velocity and other parameters, and optimize the overall design and calculation of spiral bundles.

Based on the Grey Relation Analysis of Ecological Composite Wall Seismic Performance Research

2013 ◽  
Vol 368-370 ◽  
pp. 1043-1047
Author(s):  
Yin Zhang ◽  
You Han ◽  
Shuai Liang
Keyword(s):  
Seismic Performance ◽  
Evaluation System ◽  
Design Method ◽  
Structure Design ◽  
Grey System Theory ◽  
Frame Structure ◽  
Wall Structure ◽  
Width Ratio ◽  
Grey System ◽  
Composite Wall

Ecological composite wall as ecological composite wall structure of the main stress components, the seismic performance is ecological composite wall structure seismic performance evaluation system of the main content. Based on the grey system theory, the grey correlation analysis to the key parameters (the mouth of the cave, frame structure, height to width ratio) change ecological composite wall test results are analyzed, the key parameters on the ecological composite wall the influence law of seismic performance, for choosing wall structure design method to provide basis.

Heat and Mass Transfer to Air in a Cross Flow Heat Exchanger with Surface Deluge Cooling

2016 ◽  
Vol 24 (01) ◽  
pp. 1650002 ◽  
Author(s):  
Andrea Diani ◽  
Luisa Rossetto ◽  
Roberto Dall’Olio ◽  
Daniele De Zen ◽  
Filippo Masetto
Keyword(s):  
Heat Exchanger ◽  
Heat Flow ◽  
Flow Rate ◽  
Data Center ◽  
Heat Dissipation ◽  
Cross Flow ◽  
Critical Conditions ◽  
Heat Flow Rate ◽  
External Temperature ◽  
Flow Heat

Cross flow heat exchangers, when applied to cool data center rooms, use external air (process air) to cool the air stream coming from the data center room (primary air). However, an air–air heat exchanger is not enough to cope with extreme high heat loads in critical conditions (high external temperature). Therefore, water can be sprayed in the process air to increase the heat dissipation capability (wet mode). Water evaporates, and the heat flow rate is transferred to the process air as sensible and latent heat. This paper proposes an analytical approach to predict the behavior of a cross flow heat exchanger in wet mode. The theoretical results are then compared to experimental tests carried out on a real machine in wet mode conditions. Comparisons are given in terms of calculated versus experimental heat flow rate and evaporated water mass flow rate, showing a good match between theoretical and experimental values.

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