Electromagnetic‐Thermal Bi‐directional Coupling Analysis of IEF‐DDPMM Under Different Operation Conditions and Cooling System Optimization Design

Author(s):  
Jiaxu Zhang ◽  
Bingyi Zhang ◽  
Guihong Feng
2013 ◽  
Vol 724-725 ◽  
pp. 1474-1477
Author(s):  
Xiao Ming Zhang ◽  
Yang Gao ◽  
Xiao Zhang

Applied FLUENT simulation software to research the influence of tunnel length, tunnel entrance velocity, tunnel equivalent diameter and tunnel buried depth four important factors on the tunnel wind cooling system in Shenyang area. The results show that, with the increase of tunnel length and tunnel buried depth and with the decrease of tunnel entrance velocity and tunnel equivalent diameter, the outdoor air which passed into the tunnel cooling amplitude increases. For the tunnel wind cooling system optimization design in Shenyang area and the surrounding areas, the advices are that tunnel buried depth should not be more than 6m and tunnel entrance velocity should not be more than 5m/s.


Author(s):  
Grzegorz Nowak

This paper discusses the problem of cooling system optimization within a gas turbine airfoil regarding to thermo-mechanical behavior of the component, as well as some economical aspects of turbine operation. The main goal of this paper is to show the possibilities of evolutionary approach application to the cooling system optimization. This method, despite its relatively high computational cost, seems to be a valuable tool to such technical problems. The analysis involves the optimization of location and size of internal cooling passages within an airfoil. Initially cooling is provided with circular passages and heat is transported by convection. During the optimization the number of channels can vary. The task is approached in 3D configuration. Each passage is fed with cooling air of constant parameters at the inlet. Also a constant pressure drop is assumed along the passage length. The thermal boundary conditions in passages vary with diameter and local vane temperature (passage wall temperature). The analysis is performed by means of the genetic algorithm for the optimization task and FEM for the heat transfer predictions within the component. In the present study the airfoil profile is taken as aerodynamically optimal and the objective of the search procedure is to find cooling structure variant that at given external conditions provides lower stresses, material temperature and indirectly coolant usage.


2015 ◽  
Vol 17 (3) ◽  
pp. 127 ◽  
Author(s):  
Endiah Puji Hastuti ◽  
Muhammad Subekti ◽  
Sukmanto Dibyo ◽  
M. Darwis Isnaini

ABSTRAK OPTIMASI DESAIN TERMOHIDROLIKA TERAS DAN SISTEM PENDINGIN REAKTOR RISET INOVATIF DAYA TINGGI. Implementasi reaktor inovasi telah diterapkan pada berbagai reaktor riset baru yang saat ini sedang dibangun.  Pada saat ini BATAN sedang merancang desain konseptual reaktor riset daya tinggi yang telah masuk pada tahap optimasi desain. Spesifikasi desain konseptual reaktor riset inovatif adalah reaktor tipe kolam berpendingin air dan reflektor D2O. Teras reaktor memiliki kisi 5x5 dengan 16 bahan bakar dan 4 batang kendali. Teras reaktor berada di dalam tabung berisi D2O yang berfungsi sebagai posisi iradiasi. Daya reaktor 50 MW didesain untuk membangkitkan fluks neutron termal sebesar 5x1014 n/cm2s. Teras reaktor berbentuk kompak dan menggunakan bahan bakar U9Mo-Al dengan tingkat muat uranium 7-9 gU/cm3. Desain termohidrolika yang mencakup pemodelan, perhitungan dan analisis kecukupan pendingin dibuat sinergi dengan desain fisika teras agar keselamatan reaktor terjamin. Makalah ini bertujuan menyampaikan hasil analisis perhitungan termohidrolika teras dan sistem reaktor riset inovatif pada kondisi tunak. Analisis dilakukan menggunakan program perhitungan yang telah tervalidasi, masing-masing adalah Caudvap, PARET-ANL, Fluent dan ChemCad 6.4.1. Hasil perhitungan menunjukkan bahwa pembangkitan panas yang tinggi dapat dipindahkan tanpa menyebabkan pendidihan dengan menerapkan desain teras reaktor bertekanan, di samping itu desain awal komponen utama sistem pembuangan panas yang terintegrasi telah dilakukan, sehingga konseptual desain termohidrolika RRI-50 dapat diselesaikan. Kata kunci : reaktor riset inovatif, Caudvap, PARET-ANL, Fluent, ChemCad 6.4.1.  ABSTRACT THERMALHYDRAULIC DESIGN AND COOLING SYSTEM OPTIMIZATION OF THE HIGH POWER INOVATIVE RESEARCH REACTOR. Reactor innovation has been implemented in a variety of new research reactors that currently are being built. At this time BATAN is designing a conceptual design of the high power research reactor which has entered the stage of design optimization. The conceptual design specifications of the innovative research reactor is a pool type reactor, water-cooled and reflected by D2O. The reactor core has a 5 x 5 grid with 16 fuels and 4 control rods, which is inserted into a tube containing D2O as an irradiation position. Reactor power of 50 MW is designed to generate thermal neutron flux of 5x1014 n/cm2s. The compact core reactor is using U9Mo-Al fuel with uranium loading of 7-9 gU/cm3. Thermal hydraulic design includes modeling, calculation and analysis of the adequacy of coolant created synergy with the physical design of reactor safety. This paper aims to deliver the results of thermal hydraulic calculation and system design analysis at steady state condition. The analysis was done using various calculation programs that have been validated, i.e. Caudvap, PARET-ANL, Fluent and ChemCad 6.4.1. The calculation results show that the heat generation can be transfered without causing a two phase flow boiling by applying pressurized reactor core design, while the main components of initial design system with an integrated heat dissipation has been done, to complete the conceptual design of the RRI-50 thermalhydraulics. Keywords : inovative research reactor, Caudvap, PARET-ANL, Fluent, ChemCad 6.4.1.


2021 ◽  
Vol 9 ◽  
Author(s):  
Shibin Luo ◽  
Zhichao Miao ◽  
Jian Liu ◽  
Jiawen Song ◽  
Wenxiong Xi ◽  
...  

As a promising and efficient active cooling method, double layer transpiration cooling is introduced into the design of the cooling system in the leading edge of a hypersonic vehicle. The physical model is built combined with hypersonic transpiration cooling, film cooling, heat conduction, porous media heat conduction and convection heat transfer. In addition, effects of different kinds of coolants are considered to reveal cooling mechanisms in different operation conditions. A comprehensive turbulence model validation and mesh independence study are provided. Flow characteristics caused by flow impingement, separation, transition and interaction with the cooling flows are displayed and analyzed in the work. When different kinds of coolants supplied at the same mass flow rate, the coolants with low densities, i.e., H2 and He, have the lowest peak temperature compared with the coolants with large densities, i.e., N2 and CO2. The coolants with low densities have a large ejecting velocity which provides large kinetic energy to penetrate deeply in the porous media. In addition, when the ejecting velocity is large enough, a recirculation is formed in front of the leading edge and pushes the high temperature region located in stagnation region away from the leading edge. However, when the coolants are ejected at the same velocity, the coolants with large densities exhibit better cooling performance.


Active machinery monitoring – continuous supervising, diagnosing, managing, controlling, compensating, documenting- is a process of acquiring and transferring streams of information (usually source information) about the analysed object, process, and relations between the same and the environment that can be used to realize the postulated state: knowledge creation (theory and innovation), environment melioration (harmfulness) and technical system optimization (design) - depending on technology needs and engineer imaginations. Knowledge creation comes as result of the creative action (creating). Melioration means the intentional activities of a technical system and boundary zone; activities that enhance, improve, and restore properties of the environment and not only limit technological harmfulness. Optimum comes in property of the machinery design (construction) or system state with respect to the criteria that enable rational evaluation of the state. Active monitoring, investigations into multi-disc grinders, demonstrate that it is possible to acquire knowledge of, describe and utilize, for design and structural purposes, the characteristics that indicate the relations between speeds, idle movement, loads and the indicators of motion variables in the grinding space. The objective of this example is to provide a mathematical description, optimisation of the states and changes in the grinding grains and machine space, their surface and volume during movement (idle and working movement) of the components, and design assemblies in the multi-hole grinding process.


Author(s):  
G. Bella ◽  
V. K. Krastev

The need for reliable CFD simulation tools is a key factor for today’s automotive industry, especially for what concerns aerodynamic design driven by critical factors such as the engine cooling system optimization and the reduction of drag forces, both limited by continuously changing stylistic constraints. The Ahmed body [1] is a simplified car model nowadays largely accepted as a test-case prototype of a modern passenger car because in its aerodynamic behavior is possible to recognize many of the typical features of a light duty vehicle. Several previous works have pointed out that the flow region which presents the major contribution to the overall aerodynamic drag, and which presents severe problems to numerical predictions and experimental studies as well, is the wake flow behind the vehicle model. In particular, a more exact simulation of the wake and separation process seems to be essential for the accuracy of drag predictions. In this paper a numerical investigation of flow around the Ahmed body, performed with the open-source CFD toolbox OpenFOAM®, is presented. Two different slant rear angle configurations have been considered and several RANS turbulence models, as well as different wall treatments, have been implemented on a hybrid unstructured computational grid. Pressure drag predictions and other flow features, especially in terms of flow structures and velocity field in the wake region, have been critically compared with the experimental data available in the literature and with some prior RANS-based numerical studies.


Author(s):  
Felipe A. C. Viana ◽  
Jack Madelone ◽  
Niranjan Pai ◽  
Genghis Khan ◽  
Sanghum Baik

To achieve high efficiency, modern gas turbines operate at temperatures that exceed melting points of metal alloys used in turbine hot gas path parts. Parts exposed to hot gas are actively cooled with a portion of the compressor discharge air (e.g., through film cooling) to keep the metal temperature at levels needed to meet durability requirements. However, to preserve efficiency, it is important to optimize the cooling system to use the least amount of cooling flow. In this study, film cooling optimization is achieved by varying cooling hole diameters, hole to hole spacing, and film row placements so that the specified targets for maximum metal temperature are met while preserving (or saving) cooling flow. The computational cost of the high-fidelity physics models, the large number of design variables, the large number and nonlinearity of responses impose severe challenges to numerical optimization. Design of experiments and cheap-to-evaluate approximations (radial basis functions) are used to alleviate the computational burden. Then, the goal attainment method is used for optimizing of film cooling configuration. The results for a turbine blade design show significant improvements in temperature distribution while maintaining/reducing the amount of used cooling flow.


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