3D Coupled Fluid-Solid Thermal Simulation of a Turbine Disc Through a Transient Cycle

2012 ◽  
Author(s):  
Zixiang Sun ◽  
John W. Chew ◽  
Nicholas J. Hills ◽  
Christopher J. Barnes ◽  
Antonio Guijarro Valencia
Keyword(s):  
Test Data ◽  
Industrial Applications ◽  
Cfd Modeling ◽  
Test Case ◽  
Time Step ◽  
Element Analysis ◽  
Cooling Flow ◽  
Turbine Disc ◽  
Data Provision ◽  
Rapid Transients

Thermal analysis of a turbine disc through a transient test cycle is demonstrated using 3D computational fluid dynamics (CFD) modeling for the cooling flow and 3D finite element analysis (FEA) for the disc. The test case is a 3D angular sector of the high pressure (HP) turbine assembly of a civil jet engine and includes details of the coolant flow around the blade roots. Proprietary FEA and CFD solvers are used to simulate the metal and fluid domains, respectively. Coupling is achieved through an iterative loop with smooth exchange of information between the FEA and CFD simulations at each time step, ensuring consistency of temperature and heat flux on the coupled interfaces between the metal and fluid domains. The coupled simulation can be completed within a few weeks using a PC cluster with multiple parallel CFD executions. The FEA/CFD coupled result agrees well with corresponding rig test data and the baseline 3D and 2D FEA solutions, which have been calibrated using test data. Provision of upstream boundary conditions and modeling of rapid transients are identified as areas of uncertainty. Averaging of CFD solutions and relaxation is used to overcome difficulties caused by CFD oscillations associated with flow unsteadiness. The present work supports the continued use and development of the FEA/CFD coupling method for industrial applications.

scholarly journals CFD Modeling and evaluation of a bi-stable micro-diverter valve

2018 ◽  
Vol 8 (1) ◽  
pp. 77-84 ◽  
Author(s):  
Marco A Guevara L
Keyword(s):  
Steady State ◽  
Turbulence Models ◽  
Industrial Applications ◽  
Process Efficiency ◽  
Cfd Modeling ◽  
Time Step ◽  
Time Step Size ◽  
Operation Conditions ◽  
Low Reynolds ◽  
Transient And Steady State

Micro-diverter valves are innovative and efficient devices used to generate microbubbles that can significantly enhance process efficiency in industry. Micro-diverter valves have been experimentally tested and modeled using CFD in previous works. However, a detailed CFD modeling evaluation of these valves has not been performed employing detailed turbulence modeling at transient and steady state. This article presents a three-dimensional CFD simulation and performance evaluation of a bi-stable diverted valve for microbubble generation. In the model, transient and steady state approaches were used to quantify the behavior in the valve. The κ – ε standard and κ – ε RNG turbulence models were used and compared. Different mesh configurations, mesh generation methods, and both turbulence models were evaluated to find the best set-up to simulate this valve. A brief analysis of the time-step size using the Courant number approach was also performed. Operation conditions at low Reynolds (3800) and high frequency (200 Hz) were used to assess possible industrial applications, thus setting the base for further studies. The results of this work show that at low Reynolds numbers and high frequencies, the valve is able to divert the fluid and thus it may have wider industrial applications.

Coupled Aero-Thermo-Mechanical Simulation for a Turbine Disc Through a Full Transient Cycle

2010 ◽  
Author(s):  
Zixiang Sun ◽  
John W. Chew ◽  
Nicholas J. Hills ◽  
Leo Lewis ◽  
Christophe Mabilat
Keyword(s):  
Heat Transfer ◽  
Mechanical Response ◽  
Cavity Flow ◽  
Time Step ◽  
Element Analysis ◽  
Cfd Models ◽  
Fea Model ◽  
Turbine Disc ◽  
Coupling Procedure ◽  
Efficient Coupling

Use of computational fluid dynamics (CFD) to model the complex, 3D disc cavity flow and heat transfer in conjunction with an industrial finite element analysis (FEA) of turbine disc thermo-mechanical response during a full transient cycle is demonstrated. The FEA and CFD solutions were coupled using a previously proposed efficient coupling procedure. This iterates between FEA and CFD calculations at each time step of the transient solution to ensure consistency of temperature and heat flux on the appropriate component surfaces. The FEA model is a 2D representation of high pressure (HP) and intermediate pressure (IP) turbine discs with surrounding structures. The front IP disc cavity flow is calculated using 45° sector CFD models with up to 2.8 million mesh cells. Three CFD models were initially defined for idle, maximum take-off (MTO) and cruise conditions, and these are updated by the automatic coupling procedure through the 13000 seconds full transient cycle from standstill, to idle, maximum take-off, and cruise conditions. The obtained disc temperatures and displacements are compared with an earlier standalone FEA model which used established methods for convective heat transfer modelling. It was demonstrated that the coupling could be completed using a computer cluster with 60 cores, within about two weeks. This turn around time is considered fast enough to meet design phase requirements and in validation it also compares favorably to that required to hand-match an FEA model to engine test data, which is typically several months.

Creep Life Prediction of Aircraft Turbine Disc Alloy Using Continuum Damage Mechanics

2017 ◽  
Vol 38 (1) ◽  
pp. 25-30
Author(s):  
Yan-Feng Li ◽  
Zhisheng Zhang ◽  
Chenglin Zhang ◽  
Jie Zhou ◽  
Hong-Zhong Huang
Keyword(s):  
Numerical Analysis ◽  
Test Data ◽  
Life Prediction ◽  
Damage Mechanics ◽  
Continuum Damage Mechanics ◽  
Creep Model ◽  
Continuum Damage ◽  
Creep Life ◽  
Creep Life Prediction ◽  
Turbine Disc

Abstract This paper deals with the creep characteristics of the aircraft turbine disc material of nickel-base superalloy GH4169 under high temperature. From the perspective of continuum damage mechanics, a new creep life prediction model is proposed to predict the creep life of metallic materials under both uniaxial and multiaxial stress states. The creep test data of GH4169 under different loading conditions are used to demonstrate the proposed model. Moreover, from the perspective of numerical simulation, the test data with analysis results obtained by using the finite element analysis based on Graham creep model is carried out for comparison. The results show that numerical analysis results are in good agreement with experimental data. By incorporating the numerical analysis and continuum damage mechanics, it provides an effective way to accurately describe the creep damage process of GH4169.

scholarly journals Design, Analysis and Test of a Hyperbolic Magnetic Field Voice Coil Actuator for Magnetic Levitation Fine Positioning Stage

Energies ◽  
2019 ◽  
Vol 12 (10) ◽  
pp. 1830
Author(s):  
Yiheng Zhou ◽  
Baoquan Kou ◽  
He Zhang ◽  
Lu Zhang ◽  
Likun Wang
Keyword(s):  
Magnetic Field ◽  
High Precision ◽  
Magnetic Levitation ◽  
Structural Parameters ◽  
Industrial Applications ◽  
Degree Of Freedom ◽  
Force Density ◽  
Precision Positioning ◽  
Element Analysis ◽  
Voice Coil Actuator

The multi-degree-of-freedom high-precision positioning system (MHPS) is one of the key technologies in many advanced industrial applications. In this paper, a novel hyperbolic magnetic field voice coil actuator using a rhombus magnet array (HMF-VCA) for MHPS is proposed. Benefiting from the especially designed rhombus magnet array, the proposed HMF-VCA has the advantage of excellent force uniformity, which makes it suitable for multi-degree-of-freedom high-precision positioning applications. First, the basic structure and operation principles of the HMF-VCA are presented. Second, the six-degree-of-freedom force and torque characteristic of the HMF-VCA is studied by three-dimensional finite element analysis (3-D FEA). Third, the influence of structural parameters on force density and force uniformity is investigated, which is conducive to the design and optimization of the HMF-VCA. Finally, a prototype is constructed, and the comparison between the HMF-VCA and conventional VCAs proves the advantage of the proposed topology.

scholarly journals Determination of Constraint-Modified J-R Curves for Carbon Steel Storage Tanks

2002 ◽  
Author(s):  
P.-S. Lam ◽  
Y. J. Chao ◽  
X.-K. Zhu ◽  
Y. Kim ◽  
R. L. Sindelar
Keyword(s):  
Carbon Steel ◽  
Test Data ◽  
Storage Tank ◽  
Closed Form Solution ◽  
Crack Tip ◽  
Form Solution ◽  
Fracture Parameter ◽  
Element Analysis ◽  
Crack Tip Constraint ◽  
Senb Specimen

Mechanical testing of A285 carbon steel, a storage tank material, was performed to develop fracture properties based on the constraint theory of fracture mechanics. A series of single edge-notched bend (SENB) specimen designs with various levels of crack tip constraint were used. The variation of crack tip constraint was achieved by changing the ratio of the initial crack length to the specimen depth. The test data show that the J-R curves are specimen-design-dependent, which is known as the constraint effect. A two-parameter fracture methodology is adopted to construct a constraint-modified J-R curve, which is a function of the constraint parameter, A2, while J remains the loading parameter. This additional fracture parameter is derived from a closed form solution and can be extracted from the finite element analysis for a specific crack configuration. Using this set of SENB test data, a mathematical expression representing a family of the J-R curves for A285 carbon steel can be developed. It is shown that the predicted J-R curves match well with the SENB data over an extensive amount of crack growth. In addition, this expression is used to predict the J-R curve of a compact tension specimen (CT), and reasonable agreement to the actual test data is achieved. To demonstrate its application in a flaw stability evaluation, a generic A285 storage tank with a postulated axial flaw is used. For a flaw length of 10% of the tank height, the predicted J-R curve is found to be similar to that for a SENB specimen with a short notch, which is in a state of low constraint. This implies that the use of a J-R curve from the ASTM (American Society for Testing and Materials) standard designs, which typically are high constraint specimens, may be overly conservative for analysis of fracture resistance of large structures.

Analysis of Thick-Walled Pipeline Elements Operating in Creep Conditions

2015 ◽  
Vol 712 ◽  
pp. 63-68
Author(s):  
Przemysław Osocha ◽  
Bohdan Węglowski
Keyword(s):  
Finite Element ◽  
Test Data ◽  
Creep Test ◽  
Power Plants ◽  
Steam Pressure ◽  
Creep Model ◽  
Creep Process ◽  
Fe Model ◽  
Element Analysis ◽  
Wide Range

In some coal-fired power plants, pipeline elements have worked for over 200 000 hours and increased number of failures is observed. The paper discuses thermal wear processes that take place in those elements and lead to rupture. Mathematical model based on creep test data, and describing creep processes for analyzed material, has been developed. Model has been verified for pipeline operating temperature, lower than tests temperature, basing on Larson-Miller relation. Prepared model has been used for thermal-strength calculations based on a finite element method. Processes taking place inside of element and leading to its failure has been described. Than, basing on prepared mathematical creep model and FE model introduced to Ansys program further researches are made. Analysis of dimensions and shape of pipe junction and its influence on operational element lifetime is presented. In the end multi variable dependence of temperature, steam pressure and element geometry is shown, allowing optimization of process parameters in function of required operational time or maximization of steam parameters. The article presents wide range of methods. The creep test data were recalculated for operational temperature using Larson-Miller parameter. The creep strain were modelled, used equations and their parameters are presented. Analysis of errors were conducted. Geometry of failing pipe junction was introduced to the Ansys program and the finite element analysis of creep process were conducted.

Guidelines for CFD Simulations of Spar VIM

2013 ◽  
Author(s):  
Charles Lefevre ◽  
Yiannis Constantinides ◽  
Jang Whan Kim ◽  
Mike Henneke ◽  
Robert Gordon ◽  
...  
Keyword(s):  
Reynolds Number ◽  
Test Data ◽  
Model Test ◽  
Model Tests ◽  
Full Scale ◽  
Mooring System ◽  
Time Step ◽  
Cfd Simulations ◽  
Scaled Model ◽  
Sway Motion

Vortex-Induced Motion (VIM), which occurs as a consequence of exposure to strong current such as Loop Current eddies in the Gulf of Mexico, is one of the critical factors in the design of the mooring and riser systems for deepwater offshore structures such as Spars and multi-column Deep Draft Floaters (DDFs). The VIM response can have a significant impact on the fatigue life of mooring and riser components. In particular, Steel Catenary Risers (SCRs) suspended from the floater can be sensitive to VIM-induced fatigue at their mudline touchdown points. Industry currently relies on scaled model testing to determine VIM for design. However, scaled model tests are limited in their ability to represent VIM for the full scale structure since they are generally not able to represent the full scale Reynolds number and also cannot fully represent waves effects, nonlinear mooring system behavior or sheared and unsteady currents. The use of Computational Fluid Dynamics (CFD) to simulate VIM can more realistically represent the full scale Reynolds number, waves effects, mooring system, and ocean currents than scaled physical model tests. This paper describes a set of VIM CFD simulations for a Spar hard tank with appurtenances and their comparison against a high quality scaled model test. The test data showed considerable sensitivity to heading angle relative to the incident flow as well as to reduced velocity. The simulated VIM-induced sway motion was compared against the model test data for different reduced velocities (Vm) and Spar headings. Agreement between CFD and model test VIM-induced sway motion was within 9% over the full range of Vm and headings. Use of the Improved Delayed Detached Eddy Simulation (IDDES, Shur et al 2008) turbulence model gives the best agreement with the model test measurements. Guidelines are provided for meshing and time step/solver setting selection.

A Joint-Industry Effort to Develop and Verify CFD Modeling Practice for Vortex-Induced Motion of a Deep-Draft Semi-Submersible

2021 ◽  
Author(s):  
Hyunchul Jang ◽  
Dae-Hyun Kim ◽  
Madhusuden Agrawal ◽  
Sebastien Loubeyre ◽  
Dongwhan Lee ◽  
...  
Keyword(s):  
Test Data ◽  
Model Test ◽  
Working Group ◽  
Cfd Modeling ◽  
Physical Model Test ◽  
Mooring Lines ◽  
Cfd Models ◽  
Induced Motion ◽  
Modeling Practice ◽  
Decay Tests

Abstract Platform Vortex Induced Motion (VIM) is an important cause of fatigue damage on risers and mooring lines connected to deep-draft semi-submersible floating platforms. The VIM design criteria have been typically obtained from towing tank model testing. Recently, computational fluid dynamics (CFD) analysis has been used to assess the VIM response and to augment the understanding of physical model test results. A joint industry effort has been conducted for developing and verifying a CFD modeling practice for the semi-submersible VIM through a working group of the Reproducible Offshore CFD JIP. The objectives of the working group are to write a CFD modeling practice document based on existing practices validated for model test data, and to verify the written practice by blind calculations with five CFD practitioners acting as verifiers. This paper presents the working group’s verification process, consisting of two stages. In the initial verification stage, the verifiers independently performed free-decay tests for 3-DOF motions (surge, sway, yaw) to check if the mechanical system in the CFD model is the same as in the benchmark test. Additionally, VIM simulations were conducted at two current headings with a reduced velocity within the lock-in range, where large sway motion responses are expected,. In the final verification stage, the verifiers performed a complete set of test cases with small revisions of their CFD models based on the results from the initial verification. The VIM responses from these blind calculations are presented, showing close agreement with the model test data.

A Computational Fluid Dynamics (CFD) Guided Engineering Solution for Performance Improvement of a Multistage Pump

2021 ◽  
Author(s):  
Teymour Javaherchi ◽  
Susheel Brahmeshwarkar ◽  
Raja Faruq ◽  
Chinmay Deshpande
Keyword(s):  
Performance Improvement ◽  
Test Data ◽  
Industrial Applications ◽  
Pump Efficiency ◽  
Pump Impeller ◽  
Methodology Development ◽  
Engineering Team ◽  
Initial Hypothesis ◽  
Computational Fluid Dynamics Cfd ◽  
Multistage Pump

Abstract This work will demonstrate how the Energy Recovery Inc. (ERI) engineering team improved the efficiency of a multistage pump by about 10% at the first stage, which translated into a 3% increase in the overall multistage pump efficiency; according to a set of engineering calculations and review of the archived in-house test data for the legacy multistage pumps, it was hypothesized that the performance pain-point of the pump was inefficient performance of the first stage, due to the formation of a strong pre-swirl right before its inlet. The validity of this hypothesis then was confirmed via RANS CFD simulations of the flow field inside the inlet suction housing and pump impeller. Same CFD methodology was used to evaluate multiple engineering solutions to reduce the strength of the inflow pre-swirl by modifying the inlet suction housing geometry. The obtained RANS CFD solutions guided the engineering team towards the most promising hardware modification proposal. The proposed geometrical modification of the inlet suction housing was implemented and tested on different multistage pumps. All of the test results validated the obtained RANS CFD numerical solution. The state of the art in this successful performance improvement process was first the on-point hypothesis development based on fundamentals of engineering and archived test data. Second, the proper RANS CFD methodology development to model/confirm the initial hypothesis and vet all possible engineering solutions to maximize the multistage pump efficiently and accurately. This can be a great example for various relevant turbomachinery industrial applications.

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