Coupled Aerothermodynamics Optimization for the Cooling System of a Turbine Vane

2013 ◽  
Vol 136 (5) ◽  
Author(s):  
Zhongran Chi ◽  
Jing Ren ◽  
Hongde Jiang
Keyword(s):  
Genetic Algorithm ◽  
Temperature Distribution ◽  
System Design ◽  
Cooling System ◽  
Three Dimensional ◽  
Critical Issue ◽  
Operating Conditions ◽  
Critical Parameters ◽  
Pin Fin ◽  
Optimization Search

The cooling system design for air-cooled turbines is a critical issue in modern gas turbine engineering. Advances in the computational fluid dynamics (CFD) technology and optimization methodology are providing new prospects for turbine cooling system design, in the sense that the optimum cooling system of the vanes and blades could be designed automatically by the optimization search coupled with the full three-dimensional conjugate heat transfer (CHT) analysis. An optimization platform for air-cooled turbines, which consists of the genetic algorithm (GA), a mesh generation tool (Coolmesh), and a CHT solver is presented in this paper. The optimization study was aimed at finding the optimum cooling structure for a 2nd stage vane with, simultaneously, an acceptable metal temperature distribution and limited amount of coolant. The vane was installed with an impingement and pin-fin cooling structure. The optimization search involved the design of the critical parameters of the cooling system, including the size of the impingement tube, diameter and distribution of impingement holes, and the size and distribution of the pin-fin near trailing edge. The design optimization was carried out under two engine operating conditions in order to explore the effects of different boundary conditions. A constant pressure drop was assumed within the cooling system during each optimization. To make the problem computationally faster, the simulations were approached for the interior only (solid and coolant). A weighted function of the temperature distribution and coolant mass flow was used as the objective of the single objective genetic algorithm (SOGA). The result showed that the optimal cooling system configuration with considerable cooling performance could be designed through the SOGA optimization without human interference.

Coupled Aero-Thermodynamics Optimization for the Cooling System of a Turbine Vane

2013 ◽  
Author(s):  
Zhongran Chi ◽  
Jing Ren ◽  
Hongde Jiang
Keyword(s):  
Temperature Distribution ◽  
System Design ◽  
Optimization Design ◽  
Cooling System ◽  
Critical Issue ◽  
Operating Conditions ◽  
Critical Parameters ◽  
Pin Fin ◽  
Optimization Search ◽  
Generic Algorithms

Cooling system design for the air-cooled turbine is a critical issue in modern gas turbine engineering. Advances in CFD technology and optimization methodology is providing new prospects for turbine cooling system design, that the optimum cooling system of the vanes and blades could be designed automatically by the optimization search coupled with the Conjugate Heat Transfer (CHT) analysis. An optimization platform consists of the Generic Algorithms (GA), a mesh generation tool (Coolmesh), and the CHT solver (ANSYS CFX) is presented in this paper. The optimization study was aimed at finding the optimum cooling structure for the 2nd stage vane of the E3 engine, with acceptable metal temperature distribution and limited coolant amount simultaneously. The vane was installed with impingement and pin-fin cooling structure. The optimization search involved the design of critical parameters of the cooling system, including the size of impingement tube, diameter and distribution of impingement holes, and the size and distribution of pin-fin near trailing edge. The optimization design was carried under two engine operating conditions to explore the affect of different boundary conditions. A constant pressure drop was assumed within the cooling system during each optimization. To make the problem computationally faster, the simulations were approached for the interior only (solid and coolant). A weighed function of temperature distribution and coolant mass flow was used as the objective of the Single Objective Generic Algorithms (SOGA). The result showed that the optimal cooling system configuration with considerable cooling performance could be designed through SOGA optimization without human interference.

Computational Studies on Charge Stratification and Fuel-Air Mixing in a New Two-Stroke Engine

2005 ◽  
Author(s):  
Shamit Bakshi ◽  
T. N. C. Anand ◽  
R. V. Ravikrishna
Keyword(s):  
Initial Conditions ◽  
Computational Study ◽  
Three Dimensional ◽  
The State ◽  
Operating Conditions ◽  
Injection System ◽  
Critical Parameters ◽  
Mixing Process ◽  
Air Mixing ◽  
Stroke Engine

In this paper, detailed computational study is presented which helps to understand and improve the fuel-air mixing in a new direct-mixture-injection two-stroke engine. This new air-assisted injection system-based two-stroke engine is being developed at the Indian Institute of Science, Bangalore over the past few years. It shows the potential to meet emission norms such as EURO-II and EURO-III and also deliver satisfactory performance. This work proposes a comprehensive strategy to study the air-fuel mixing process in this engine and shows that this strategy can be potentially used to improve the engine performance. A three-dimensional compressible flow code with standard k–ε turbulence model with wall functions is developed and used for this modeling. To account for the moving boundary or piston in the engine cylinder domain, a non-stationary and deforming grid is used in this region with stationary cells in the ports and connecting ducts. A flux conservation scheme is used in the domain interface to allow the in-cylinder moving mesh to slide past the fixed port meshes. The initial conditions for flow parameters are taken from the output of a three-dimensional scavenging simulation. The state of the inlet charge is obtained from a separate modeling of the air-assisted injection system of this engine. The simulation results show that a large, near-stoichiometric region is present at most operating conditions in the cylinder head plane. The state of the in-cylinder charge at the onset of ignition is studied leading to a good understanding of the mixing process. In addition, sensitivity of two critical parameters on the mixing and stratification is investigated. The suggested parameters substantially enhance the flammable proportion at the onset of combustion. The predicted P–θ from a combustion simulation supports this recommendation.

Thermal Convection and Stress Analysis of the Cooling System for a Terahertz Radiation Detector

2015 ◽  
Author(s):  
Angela Wu ◽  
Arturo Pacheco-Vega ◽  
Jeanette Cobian
Keyword(s):  
Fluid Flow ◽  
Laser Irradiation ◽  
Cooling System ◽  
Rectangular Channel ◽  
Radiation Detector ◽  
Three Dimensional ◽  
Operating Conditions ◽  
Temperature Fields ◽  
Stress Strain ◽  
Direct Laser

Detailed three-dimensional numerical simulations have been carried out to find the velocity and temperature fields, in combination with shear and normal stresses, of the fluid flow inside a rectangular channel with large aspect-ratio. The channel under analysis is aimed to cool a thermochromic liquid crystal material (TLC) that is able to capture laser irradiation in the terahertz range. The TLC is manufactured on an extremely-thin substrate. The overall objective of the cooling system is to maintain a nearly-homogeneous temperature of the TLC-domain that is not exposed to the direct laser irradiation, while minimizing the deformation in the TLC caused by the fluid-solid interaction. The fluid flow, stress-strain and heat transfer simulations are carried out on the basis of three-dimensional Navier-Stokes and energy equations for an incompressible flow, coupled with the stress-strain equation for the TLC-layer, to determine values of velocity, pressure and temperature for the fluid inside the channel and the stresses and deformation of the TLC layer, under different operating conditions. These values are then used to find, from a specific set, the value of the channel gap that enables a nearly-uniform temperature distribution in the fluid and the least amount of deformation in the solid layer, within the expected operating conditions. Results from this analysis indicate that, for all the inlet velocities considered, there is a common value of the channel gap, that represents the optimum for the cooling system.

Polymer Electrolyte Fuel Cell Design Based on Three-Dimensional Computational Fluid Dynamics Modeling

2009 ◽  
Vol 6 (2) ◽  
Author(s):  
Stefano Cordiner ◽  
Simon Pietro Lanzani ◽  
Vincenzo Mulone ◽  
Marco Chiapparini ◽  
Angelo D’Anzi ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Fuel Cell ◽  
Polymer Electrolyte ◽  
Cooling System ◽  
Three Dimensional ◽  
Design Procedure ◽  
Operating Conditions ◽  
Polymer Electrolyte Fuel Cell ◽  
Dynamics Modeling

An entirely numerical design procedure, based on computational fluid dynamics, is introduced to evaluate the performance of different polymer electrolyte fuel cell layouts and sets of operating conditions for assigned target parameters in terms of performance. The design procedure has been applied to a coflow design, characterized by large active area (500 cm2), moderate temperature (70°C), liquid cooling, and metal supporting. The role of heat transfer between the cell and the cooling system is analyzed to properly address the influence of operating conditions on power density and flooding via a comprehensive parametric analysis.

Cooling Structure Optimization for a Rib-Roughed Channel in a Turbine Rotor Blade

2013 ◽  
Author(s):  
Zhongran Chi ◽  
Jing Ren ◽  
Hongde Jiang
Keyword(s):  
Rotor Blade ◽  
Cooling System ◽  
Rectangular Channel ◽  
Turbine Blades ◽  
Critical Issue ◽  
Turbine Rotor ◽  
Optimization Study ◽  
Cooling Design ◽  
Rib Arrangement ◽  
Optimization Search

Cooling design for the air-cooled turbine blades is a critical issue in modern gas turbine engineering. Advances in CFD technology is providing new prospects for turbine cooling design, as the optimum cooling structures of the blades could be designed through the optimization search coupled with the Conjugate Heat Transfer (CHT) analysis. In this paper, the optimization study for the rib arrangement of a rib-roughed channel in a rotor blade is discussed. The optimization study introduced is realized utilizing a parametric analysis platform, which consists of the parametric design and mesh generation tool and the commercial CHT solver ANSYS CFX. For the optimization study, firstly a group of Design of Experiments (DoE) analysis of a rib-roughed rectangular channel is performed in order to find the optimum rib arrangement and to explore the objective of the optimization search. Then, the optimization search of the optimum rib arrangement is performed for a rib-roughed channel within a rotor blade based on the multi-island Genetic Algorithms (GA) of iSIGHT. During optimization search, a constant pressure drop is assumed within the cooling system, and the CHT simulations are approached for the interior only in order to make the search computationally faster. According to the DoE analysis, minimizing the averaged wall temperature on blade surface is chosen as the optimization objective for the design of rib arrangement. The results of the GA search shows that the optimal rib arrangement with best cooling performance can be decided, and the optimal mass flow rate for the cooling channel is found simultaneously. The optimum schemes of the rib arrangement found by the DoE analysis and GA search are quite identical, which further validates the feasibility of design optimization for the blade cooling structure with the GA and CHT simulations.

Numerical Analysis of Flow at Water Jacket of an Internal Combustion Engine

2011 ◽  
Vol 282-283 ◽  
pp. 702-705 ◽  
Author(s):  
De Zhi Zhang ◽  
Ying Ai Jin ◽  
De Yuan Su ◽  
Qing Gao
Keyword(s):  
Two Phase Flow ◽  
Cooling System ◽  
Combustion Engine ◽  
Three Dimensional ◽  
Operating Conditions ◽  
Phase Flow ◽  
Three Dimensional Model ◽  
Two Phase ◽  
Water Jacket ◽  
Model And Simulation

With the increasing degree of the enhancement of engine, engine cooling system design is considered particularly important. This paper used an established three-dimensional model of an engine water jacket to study, and used UDF function in the two-phase flow of the CFD, describe the mathematical model and simulation the engine at different operating conditions, and get the water jacket flow rate transfer thermal process. Finally, the results of the relationship between the engine water jacket of boiling heat transfer and flow velocity have been studied, and the importance of using two-phase flow model has been summarized.

Three-dimensional topology optimization of thermal-fluid-structural problems for cooling system design

2020 ◽  
Vol 62 (6) ◽  
pp. 3347-3366
Author(s):  
Minghao Yu ◽  
Shilun Ruan ◽  
Junfeng Gu ◽  
Mengke Ren ◽  
Zheng Li ◽  
...  
Keyword(s):  
Topology Optimization ◽  
System Design ◽  
Cooling System ◽  
Three Dimensional ◽  
Structural Problems

scholarly journals A Simplified Program to Predict the Temperature Distribution in Gas Turbine Components as a Function of the Mission Profile of the Aircraft

1999 ◽  
Author(s):  
Alwyn F. Naudé ◽  
Jan A. Visser
Keyword(s):  
Temperature Distribution ◽  
Gas Turbines ◽  
Thermal Loading ◽  
Guide Vane ◽  
Three Dimensional ◽  
Operating Conditions ◽  
Test Case ◽  
Nozzle Guide ◽  
Mission Profile

One of the main thrusts of the modern aerospace industry is to reduce the operating costs of aircraft. This requires a longer on-wing time for the gas turbines and subsequently reduced maintenance. Such a program can only be effectively implemented if the effects of operating conditions on the aircraft can be evaluated continuously. This paper presents a simplified computer program, operating on a personal computer, to predict the temperature distribution in components as a function of the operating condition of the aircraft. This information is then used to determine the deterioration of the engine under the specified operating conditions. The program consists of a simplified model to calculate the conditions in the different modules of the engine as a function of parameters like throttle position, altitude, speed of the aircraft etc. The detailed heat transfer to components is calculated using simplified analytical formulations accounting for three-dimensional effects. As a test case, the temperature change on a semi-cooled nozzle guide vane (NGV) is shown as the engine accelerates to full load conditions. It can be concluded that this approach produces realistic values for the thermal loading on components that can be used to predict long-term engine deterioration.

Stability of Laminated Composites

1992 ◽  
Vol 45 (2) ◽  
pp. 81-101 ◽  
Author(s):  
A. N. Guz’ ◽  
Vik N. Chekhov
Keyword(s):  
Composite Materials ◽  
Three Dimensional ◽  
Laminated Composite ◽  
Operating Conditions ◽  
Critical Parameters ◽  
Characteristic Classes ◽  
Deformable Solid ◽  
Stability Problems ◽  
Laminated Composite Materials ◽  
Laminated Materials

The characteristic special feature of deformation behavior of modern laminated composite materials and structural elements fabricated from these materials, at current levels of loading and operating conditions is the occurrence of the purely three-dimensional stress-deformed state. In this process some specific mechanical phenomena and effects may occur, which is impossible to describe within the framework of applied or approximate approaches existing currently in deformable solid body mechanics. The structure of massive laminated materials may be included in this class of phenomena when the critical parameters of the problem depend only on the ratio between mechanical and geometrical characteristics of single layers and are independent of the dimensions and the form of the total laminated body as a whole. Since this phenomenon may be the beginning of the process of fracture of these materials, and the loss of the load-carrying capacity of structure elements fabricated from them, we consider below, in three-dimensional formulation, the problem of the surface and internal instability in laminated composite materials under compressive surface loads. The classification of the existing types of stability problems is presented for laminated materials and approaches for their solution presented in the literature. On the basis of three-dimensional linearized stability theory, within the framework of the piecewise-homogeneous media model, the general formulation of the most characteristic classes of stability problems of laminated materials is given in Lagrangian coordinates at small and finite, homogeneous and inhomogeneous precritical deformation. Analytic and variational methods of investigation of formulated problems are given with application to various models of laminated bodies models, in accordance with accepted stability criteria. The accuracy of these models is evaluated, based on the example of the solution of certain model problems; the range of application is given for existing applied and approximate approaches to the analysis of formulated problems. Results of solution of specific problems are given; specific mechanical effects, characteristic for the phenomenon considered, are found. Recommendations are formulated for engineering design and computational methods. New promising areas of research are pointed out for the problem of laminated composite materials stability.

Investigations of the three-dimensional temperature field of journal bearings considering conjugate heat transfer and cavitation

2019 ◽  
Vol 71 (1) ◽  
pp. 109-118 ◽  
Author(s):  
Qiang Li ◽  
Shuo Zhang ◽  
Yujun Wang ◽  
Wei-Wei Xu ◽  
Zhenbo Wang
Keyword(s):  
Temperature Distribution ◽  
Conjugate Heat Transfer ◽  
Radial Direction ◽  
Journal Bearing ◽  
Three Dimensional ◽  
Journal Bearings ◽  
Operating Conditions ◽  
Temperature Zone ◽  
Content Type ◽  
Higher Temperature

Purpose The growing demand of efficiency and economy has led to a dramatic increase of the operating speed of the journal bearing, with a higher temperature distribution. This paper aims to investigate the three-dimensional temperature distribution of journal bearings. Design/methodology/approach A thermo-hydrodynamic lubrication model of a journal bearing was established based on the full 3D CFD method. A two-sided wall was used to include the conjugate heat transfer effect. The temperature-dependent characteristics of lubrication and cavitation impact were also included. The simulation results well agreed with the experimental results. Based on this method, the three-dimensional temperature distribution was analyzed under different operating conditions. Findings The temperature distribution in the radial direction had a difference. An increase of speed and de-crease of inlet temperature promoted temperature differences in the higher temperature zone and the increasing temperature zone, respectively. However, the inlet pressure had less influence on these differences. The temperature distribution was basically the same at a lower bearing conductivity. As the conductivity increased, the radial temperature difference was increased. Originality/value The temperature distribution in the radial direction was found under different operating conditions, and the present research provides references to understand the three-dimensional temperature distribution of journal bearings.

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