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Articles 211 - 240 of 321
Full-Text Articles in Mechanical Engineering
Experimental Testing And Performance Analysis Of "Room Air Cleaners", Pavan Kumar Mudiya
Experimental Testing And Performance Analysis Of "Room Air Cleaners", Pavan Kumar Mudiya
ETD Archive
HMI industries are the manufacture of the air cleaners and vacuum cleaners, in which a solution is adapted for the current model of the volute to the new design of the volute in order to calculate the "Clean Air Delivery rate" and qualify for the "Energy Star requirements". For the above model to be employed as a Energy Star certificate, a test rig was made in which "air velocity" and "flow rate" was calculated for the three different air cleaners in two cases i.e. (i) three different air cleaners with different filters and different rpm's (ii) three different air cleaners …
Radiation View Factors Between A Disk And The Interior Of A Class Of Axisymmetric Bodies Including Converging Diverging Rocket Nozzles, Mark Richard Murad
Radiation View Factors Between A Disk And The Interior Of A Class Of Axisymmetric Bodies Including Converging Diverging Rocket Nozzles, Mark Richard Murad
ETD Archive
A general symbolic exact analytic solution is developed for the radiation view factors including shadowing by the throat between a divergence thin gas disk between the combustion chamber and the beginning of the rocket nozzle radiating energy to the interior downstream of the nozzle contour for a class of coaxial axisymmetric converging diverging rocket nozzles. The radiation view factors presented in this thesis for the projection which are blocked or shadowed through the throat radiating downstream to the contour have never been presented before in the literature. It was found that the curvature of the function of the contour of …
Application Of Reverse Engineering And Rapid Prototyping To Casting, Venkat Deepak Kolar
Application Of Reverse Engineering And Rapid Prototyping To Casting, Venkat Deepak Kolar
ETD Archive
The automotive industry has an increasing need for the re manufacturing of spare parts through reverse engineering. In this thesis we will review the techniques used in Fused Deposition Modeling system for the reverse engineering of vintage automotive parts. The objective of the project is to be able to generate part-to-CAD and CAD-to-part reconstruction of the original part for future usage. These newly created 3D models will be added to the 3D Part Database. The integration of reverse engineering and rapid prototyping is being used for getting product to the market quickly by resolving a long-standing conflict between design and …
Probabilistic Finite Element Heat Transfer And Structural Analysis Of A Cone-Cylinder Pressure Vessel, Omar Haddad
Probabilistic Finite Element Heat Transfer And Structural Analysis Of A Cone-Cylinder Pressure Vessel, Omar Haddad
ETD Archive
Stress analysis of a cone-cylinder pressure vessel was computationally simulated by a finite element method and probabilistically evaluated in view of the several uncertainties in the performance parameters. Cumulative distribution functions and sensitivity factors were computed for overall Von Mises stresses due to the structural and thermodynamic random variables. These results can be used to quickly identify the most critical design variables in order to optimize the design and make it cost effective. The analysis leads to the selection of the appropriate measurements to be used in structural and heat transfer analysis and to the identification of both the most …
Mathematical Analysis Of A Geothermal System, Ivan P. Erceg
Mathematical Analysis Of A Geothermal System, Ivan P. Erceg
ETD Archive
The issue being examined is to design a more economical and efficient therefore superior geothermal system than currently in use in industry. Current geothermal systems are designed and built 300 feet into the ground. After researching ground temperature gradients for Ohio we found out that below 10 feet of depth, the temperature varies by 1 degree Fahrenheit per 100 feet depth. Our goal is to utilize the heat as close to the surface as possible and greatly reduce the need to dig so deeply into the ground. The procedure used to go about designing a superior geothermal system is to …
Creating A Reinforcement Learning Controller For Functional Electrical Stimulation Of A Human Arm, Philip S. Thomas, Michael Branicky, Antonie Van Den Bogert, Kathleen Jagodnik
Creating A Reinforcement Learning Controller For Functional Electrical Stimulation Of A Human Arm, Philip S. Thomas, Michael Branicky, Antonie Van Den Bogert, Kathleen Jagodnik
Mechanical Engineering Faculty Publications
Clinical tests have shown that the dynamics of a human arm, controlled using Functional Electrical Stimulation (FES), can vary significantly between and during trials. In this paper, we study the application of Reinforcement Learning to create a controller that can adapt to these
changing dynamics of a human arm. Development and tests were done in simulation using a two-dimensional arm model and Hill-based muscle dynamics. An actor-critic architecture is used with artificial neural networks for both the actor and the critic. We begin by training it using a Proportional Derivative (PD) controller as a supervisor. We then make clinically relevant …
Helical Axes Of Skeletal Knee Joint Motion During Running, Antonie J. Van Den Bogert, C. Reinschmidt, A. Lundberg
Helical Axes Of Skeletal Knee Joint Motion During Running, Antonie J. Van Den Bogert, C. Reinschmidt, A. Lundberg
Mechanical Engineering Faculty Publications
The purpose of this study was to determine the changes in the axis of rotation of the knee that occur during the stance phase of running. Using intracortical pins, the three-dimensional skeletal kinematics of three subjects were measured during the stance phase of five running trials. The stance phase was divided into equal motion increments for which the position and orientation of the finite helical axes (FHA) were calculated relative to a tibial reference frame. Results were consistent within and between subjects. At the beginning of stance, the FHA was located at the midepicondylar point and during the flexion phase …
Multiplexed Predictive Control Of A Large Commercial Turbofan Engine, Hanz Richter, Anil V. Singaraju, Jonathan S. Litt
Multiplexed Predictive Control Of A Large Commercial Turbofan Engine, Hanz Richter, Anil V. Singaraju, Jonathan S. Litt
Mechanical Engineering Faculty Publications
Model predictive control is a strategy well-suited to handle the highly complex, nonlinear, uncertain, and constrained dynamics involved in aircraft engine control problems. However, it has thus far been infeasible to implement model predictive control in engine control applications, because of the combination of model complexity and the time allotted for the control update calculation. In this paper, a multiplexed implementation is proposed that dramatically reduces the computational burden of the quadratic programming optimization that must be solved online as part of the model-predictive-control algorithm. Actuator updates are calculated sequentially and cyclically in a multiplexed implementation, as opposed to the …
On Internal Cone Cracks Induced By Conical Indentation In Brittle Materials, J. Yan, Anette M. Karlsson, X. Chen
On Internal Cone Cracks Induced By Conical Indentation In Brittle Materials, J. Yan, Anette M. Karlsson, X. Chen
Mechanical Engineering Faculty Publications
The conditions for cone cracks to develop due to a conical indentation are investigated. Axisymmetric numerical simulations, based on the finite element method, are conducted, assuming a linear-elastic, perfectly plastic material. A superposition scheme is employed to simulate a range of crack geometries, including various lengths and orientations. The results indicate that the class of cracks investigated is prone to develop internally in brittle materials. Based on a reversed analysis, a new technique is proposed for measuring the fracture toughness in bulk material and thick coatings through one simple indentation test when the cone crack appears.
The Effect Of Tibiofemoral Loading On Proximal Tibiofibular Joint Motion, Jacob Scott, Ho Lee, Wael Barsoum, Antonie J. Van Den Bogert
The Effect Of Tibiofemoral Loading On Proximal Tibiofibular Joint Motion, Jacob Scott, Ho Lee, Wael Barsoum, Antonie J. Van Den Bogert
Mechanical Engineering Faculty Publications
The human proximal tibiofibular joint (PTFJ) and its relationship to overall knee joint mechanics have been largely unexplored. This study describes force/displacement data from experiments done on four human cadaveric knee specimens and general conclusions obtained with the help of a statistical modeling technique. Specimens were rigidly affixed at the tibia to a force plate and the femur was attached to a custom made device allowing for manual load application. Motion of the fibular head was tracked relative to the tibial plateau by means of reflective markers and a high speed digital camera synchronized with the force plate data stream. …
On The Reference Length And Mode Mixity For A Bimaterial Interface, A. Agrawal, Anette M. Karlsson
On The Reference Length And Mode Mixity For A Bimaterial Interface, A. Agrawal, Anette M. Karlsson
Mechanical Engineering Faculty Publications
We investigate properties that govern interfacial fracture within the framework of linear elastic fracture mechanics, including interfacial fracture toughness, mode mixity,and the associated reference length. The reference length describes the arbitrary location where the mode mixity is evaluated, ahead ofthe crack tip, in a bimaterial system. A method for establishing a reference length that is fixed for a given bimaterial system is proposed. This is referred to as the“characteristic reference length,” with the associated “characteristic mode mixity.” The proposed method is illustrated with an experimental investigation, utilizing a four-point bend test of a bimaterial system.
Multiaxial Thermo-Mechanical Fatigue On Material Systems For Gas Turbines, M. Bartsch, B. Baufeld, M. Henzelmann, Anette M. Karlsson, S. Dalkilic, L. Chernova
Multiaxial Thermo-Mechanical Fatigue On Material Systems For Gas Turbines, M. Bartsch, B. Baufeld, M. Henzelmann, Anette M. Karlsson, S. Dalkilic, L. Chernova
Mechanical Engineering Faculty Publications
Material systems made from nickel based superalloys with protective coatings have been tested in thermo-mechanical fatigue with superposed thermal gradients, which generated multiaxial stress states. The testing conditions were selected for simulating the fatigue loading in the wall of an internally cooled gas turbine blade of an aircraft engine. After thermo-mechanical testing the damage behaviour of the materials has been investigated by means of microscopic methods. The laboratory experiments have been accompanied by numerical simulations. Based on the results of the simulations and observed damage features the test parameters in subsequent laboratory tests have been controlled to facilitate the validation …
Mechanical Behavior Of Fuel Cell Membranes Under Humidity Cycles And Effect Of Swelling Anisotropy On The Fatigue Stresses, Ahmet Kusoglu, Anette M. Karlsson, Michael H. Santare, Simon Cleghorn, William B. Johnson
Mechanical Behavior Of Fuel Cell Membranes Under Humidity Cycles And Effect Of Swelling Anisotropy On The Fatigue Stresses, Ahmet Kusoglu, Anette M. Karlsson, Michael H. Santare, Simon Cleghorn, William B. Johnson
Mechanical Engineering Faculty Publications
The mechanical response of proton exchange membranes in a fuel cell assembly is investigated under humidity cycles at a constant temperature (85°C). The behavior of the membrane under hydration–dehydration cycles is simulated by imposing a humidity gradient from the cathode to the anode. Linear elastic, plastic constitutive behavior with isotropic hardening and temperature and humidity dependent material properties are utilized in the simulations for the membrane. The evolution of the stresses and plastic deformation during the humidity cycles are determined using finite element analysis for two clamping methods and various levels of swelling anisotropy. The membrane response strongly depends on …
Review Of Rotordynamics, Jerzy T. Sawicki
Review Of Rotordynamics, Jerzy T. Sawicki
Mechanical Engineering Faculty Publications
Book Review of Rotordynamics, by Agnieszka (Agnes) Muszynska. CRC Press, Taylor & Francis Group, Boca Raton, FL, 2005, 1128 pp., ISBN: 0-8247-2399-6
Modeling And Performance Evaluation Of Machining Spindle With Active Magnetic Bearings, Jerzy T. Sawicki, Eric H. Maslen, Kenneth R. Bischof
Modeling And Performance Evaluation Of Machining Spindle With Active Magnetic Bearings, Jerzy T. Sawicki, Eric H. Maslen, Kenneth R. Bischof
Mechanical Engineering Faculty Publications
Active magnetic bearings (AMBs) are increasingly employed in the machine tool industry to exploit their advantages over classical bearings such as high speed capability, rotation accuracy, high stiffness, and accurate displacement tracking capability. Furthermore, the possibility of on-line monitoring of the machining process (e.g., cutting force measurement, tool wear) makes AMB spindles very appealing to the High-Speed Machining (HSM) industry. Despite significant progress already reached in HSM technology, there remain numerous open challenges in modeling and control of magnetic bearings as applied to machining spindles. These include optimum control given AMB magnetic saturation levels, management of nonlinear effects, reduction of …
Determining Plastic Properties Of A Material With Residual Stress By Using Conical Indentation, J. Yan, Anette M. Karlsson, X. Chen
Determining Plastic Properties Of A Material With Residual Stress By Using Conical Indentation, J. Yan, Anette M. Karlsson, X. Chen
Mechanical Engineering Faculty Publications
Instrumented indentation is a popular method for determining mechanical properties in engineering materials. However, there are several shortcomings and challenges involved with correctly interpreting the test results. We propose here a unified method for evaluating instrumented indentation testing conducted on a material that exhibits both strain hardening under yielding and which is subjected to uniform, equi-biaxial residual stresses. The proposed method is based on extensive finite element simulations that relate the parameter-space spanned by Young’s modulus, yield strength, strain hardening and residual stress, to the response from the indentation test. Based on reverse analysis, the proposed method can be used …
Determining Equi-Biaxial Residual Stress And Mechanical Properties From The Force-Displacement Curves Of Conical Microindentation, J. Yan, X. Chen, Anette M. Karlsson
Determining Equi-Biaxial Residual Stress And Mechanical Properties From The Force-Displacement Curves Of Conical Microindentation, J. Yan, X. Chen, Anette M. Karlsson
Mechanical Engineering Faculty Publications
An alternative, improved method to determine mechanical properties from indentation testing is presented. This method can determine the elastic modulus, yield strength and equi-biaxial residual stress from one simple test. Furthermore,the technique does not require the knowledge of the contact area during indentation, a parameter that is hard to determine for highly elastic material. The evaluation technique is based on finite element analyses, where explicit formulations are established to correlate the parameter groups governing indentation on stressed specimens.
Model-Based Estimation Of Muscle Forces Exerted During Movements, Ahmet Erdemir, Scott Mclean, Walter Herzog, Antonie J. Van Den Bogert
Model-Based Estimation Of Muscle Forces Exerted During Movements, Ahmet Erdemir, Scott Mclean, Walter Herzog, Antonie J. Van Den Bogert
Mechanical Engineering Faculty Publications
Estimation of individual muscle forces during human movement can provide insight into neural control and tissue loading and can thus contribute to improved diagnosis and management of both neurological and orthopaedic conditions. Direct measurement of muscle forces is generally not feasible in a clinical setting, and non-invasive methods based on musculoskeletal modeling should therefore be considered. The current state of the art in clinical movement analysis is that resultant joint torques can be reliably estimated from motion data and external forces (inverse dynamic analysis). Static optimization methods to transform joint torques into estimates of individual muscle forces using musculoskeletal models, …
A Microfabricated Segmented-Involute-Foil Regenerator For Enhancing Reliability And Performance Of Stirling Engines: Phase Ii Final Report For The Radioisotope Power Conversion Technology Nra Contract Nas3-03124, Mounir B. Ibrahim, Daniel Danila, Terrence Simon, Susan Mantell, Liyong Sun, David Gedeon, Songgang Qiu, Gary Wood, Kevin Kelly, Jeffrey Mclean
A Microfabricated Segmented-Involute-Foil Regenerator For Enhancing Reliability And Performance Of Stirling Engines: Phase Ii Final Report For The Radioisotope Power Conversion Technology Nra Contract Nas3-03124, Mounir B. Ibrahim, Daniel Danila, Terrence Simon, Susan Mantell, Liyong Sun, David Gedeon, Songgang Qiu, Gary Wood, Kevin Kelly, Jeffrey Mclean
Mechanical Engineering Faculty Publications
An actual-size microfabricated regenerator comprised of a stack of 42 disks, 19 mm diameter and 0.25 mm thick, with layers of microscopic, segmented, involute-shaped flow channels was fabricated and tested. The geometry resembles layers of uniformly-spaced segmented-parallel-plates, except the plates are curved. Each disk was made from electro-plated nickel using the LiGA process. This regenerator had feature sizes close to those required for an actual Stirling engine but the overall regenerator dimensions were sized for the NASA/Sunpower oscillating-flow regenerator test rig. Testing in the oscillating-flow test rig showed the regenerator performed extremely well, significantly better than currently used random-fiber material, …
A Microfabricated Involute-Foil Regenerator For Stirling Engines, Roy C. Tew, Mounir B. Ibrahim, Daniel Danila, Terrence W. Simon, Susan Mantell, Liyong Sun, David Gedeon, Kevin Kelly, Jeffrey Mclean, Gary Wood, Songgang Qiu
A Microfabricated Involute-Foil Regenerator For Stirling Engines, Roy C. Tew, Mounir B. Ibrahim, Daniel Danila, Terrence W. Simon, Susan Mantell, Liyong Sun, David Gedeon, Kevin Kelly, Jeffrey Mclean, Gary Wood, Songgang Qiu
Mechanical Engineering Faculty Publications
A segmented involute-foil regenerator has been designed, microfabricated and tested in an oscillating-flow rig with excellent results. During the Phase I effort, several approximations of parallel-plate regenerator geometry were chosen as potential candidates for a new microfabrication concept. Potential manufacturers and processes were surveyed. The selected concept consisted of stacked segmentedinvolute- foil disks (or annular portions of disks), originally to be microfabricated from stainless-steel via the LiGA (lithography, electroplating, and molding) process and EDM. During Phase II, re-planning of the effort led to test plans based on nickel disks, microfabricated via the LiGA process, only. A stack of nickel segmented-involute-foil …
Performance Characteristics Of An Innovative Wind Power System, David James Kerze
Performance Characteristics Of An Innovative Wind Power System, David James Kerze
ETD Archive
This project entails a study of a wind energy recovery system that utilizes a unique three-dimensional spiral structure to amplify wind speed and direct it toward pluralities of turbines. The system is comprised of an outer spiral shell, internal support structure, turbines, and mechanisms for positioning the turbines to face the prevailing wind. Computational Fluid Dynamics (CFD) analyses were conducted to determine the wind speed amplification factors as a result of a simulated wind flow around the spiral structure. To ensure accuracy of the results, state of the art CFD techniques were applied using Gambit 2.2.30 and Fluent 6.2.16. Specifically, …
Flow Of Sub-Cooled Cryogens Through A Joule-Thomson Device: Investigation Of Metastability Conditions, John M. Jurns
Flow Of Sub-Cooled Cryogens Through A Joule-Thomson Device: Investigation Of Metastability Conditions, John M. Jurns
ETD Archive
Cryogenic fluid systems are fundamental to space flight architecture. Due to the unique properties of cryogenic fluids and the environments in which they operate for space flight, cryogenic fluid management systems must be developed to maintain these fluids at conditions in which they can be utilized. Liquid oxygen boils at 90 K, and liquid hydrogen boils at 20 K. Significant care must be taken to provide a thermal management system that prevents heat entering these fluids with consequential adverse effects on the performance of the cryogenic fluid systems. One critical component of a cryogenic thermal management system is a Joule-Thomson …
Acl Injuries: Do We Know The Mechanisms?, Antonie J. Van Den Bogert, Scott G. Mclean
Acl Injuries: Do We Know The Mechanisms?, Antonie J. Van Den Bogert, Scott G. Mclean
Mechanical Engineering Faculty Publications
Injuries of the anterior cruciate ligament (ACL) remain a frequent occurrence in many sports activities. Recent research has identified risk factors, and prevention strategies are being developed based on these findings. There is, however, still a limited understanding of the actual injury mechanisms. In this presentation we will review the current knowledge on ACL injury mechanisms, and identify needs and opportunities for further research.
Robust Positively Invariant Cylinders In Constrained Variable Structure Control, Hanz Richter, Brian D. O'Dell, Eduardo A. Misawa
Robust Positively Invariant Cylinders In Constrained Variable Structure Control, Hanz Richter, Brian D. O'Dell, Eduardo A. Misawa
Mechanical Engineering Faculty Publications
This paper proposes the use of cylinders as primary invariant sets to be used in certain state-constrained control designs. Following the idea originally introduced by O'Dell, the primary invariant set is intersected with the state constraints to yield sets which retain the invariance under some conditions. Although several results presented here apply to fairly general nonlinear systems and primary invariant sets of any shape, the focus is on constrained sliding-mode control (SMC) using infinite cylinders as the primary invariant set. Their use is motivated by a coordinate transformation where the sliding motion is decoupled from the overall convergence to the …
Modeling Failures Of Thermal Barrier Coatings, Anette M. Karlsson
Modeling Failures Of Thermal Barrier Coatings, Anette M. Karlsson
Mechanical Engineering Faculty Publications
Thermal barrier coatings are commonly used in high temperature parts of gas turbines, to protect the underlying metal substrate from deterioration during high temperature exposure. Unfortunately, the coatings fail prematurely, preventing the design engineers to fully utilize their implementation. Due to the complexity of the coatings, there are many challenges involved with developing failure hypotheses for the failures. This paper reviews some aspects of the current stateof- the-art on modeling failures of thermal barrier coatings, focusing on mechanics based models (such as finite element simulations) where the material physics is incorporated (such as oxidation and diffusion).
Time-Economic Lifetime Assessment For High Performance Thermal Barrier Coating Systems, Marion Bartsch, Bernd Baufeld, S. Dalkilic, Iulian Mircea, K. Lambrinou, T. Leist, J. Yan, Anette M. Karlsson
Time-Economic Lifetime Assessment For High Performance Thermal Barrier Coating Systems, Marion Bartsch, Bernd Baufeld, S. Dalkilic, Iulian Mircea, K. Lambrinou, T. Leist, J. Yan, Anette M. Karlsson
Mechanical Engineering Faculty Publications
Strategies for time-economic lifetime assessment of thermal barrier coatings (TBC) in service are described and discussed on the basis of experimental results, achieved on material systems with coatings applied by electron beam physical vapour deposition. Service cycles for gas turbine blades have been simulated on specimens in thermo-mechanical fatigue tests, accelerating the fatigue processes by an increase of load frequency. Time dependent changes in the material system were imposed by a separate ageing, where the samples were pre-oxidized prior to the fatigue test. Results of thermo-mechanical fatigue tests on pre-aged and as-coated specimens gave evidence of interaction between fatigue and …
A Simple Numerical Method Of Cycle Jumps For Cyclically Loaded Structures, D. Cojocaru, Anette M. Karlsson
A Simple Numerical Method Of Cycle Jumps For Cyclically Loaded Structures, D. Cojocaru, Anette M. Karlsson
Mechanical Engineering Faculty Publications
A method for accelerated numerical simulations of structures subjected to cyclic loading is investigated. Of particular interest is a class of structures where the structural properties evolve with time. The proposed method is based on conducting detailed finite element analysis for a set of cycles to establish a trend line, extrapolating the trend line spanning many cycles, and use the extrapolated state as initial state for additional FEA simulations. This includes a control function that automatically monitors the length of the cycle jump to ensure a realistic solution. We compare the proposed method to a reference calculation, where all incremental …
Mechanical Response Of Fuel Cell Membranes Subjected To A Hygro-Thermal Cycle, Ahmet Kusoglu, Anette M. Karlsson, Michael H. Santare, Simon Cleghorn, William B. Johnson
Mechanical Response Of Fuel Cell Membranes Subjected To A Hygro-Thermal Cycle, Ahmet Kusoglu, Anette M. Karlsson, Michael H. Santare, Simon Cleghorn, William B. Johnson
Mechanical Engineering Faculty Publications
The mechanical response of fuel cell proton exchange membranes subjected to a single hygro-thermal duty cycle in a fuel cell assembly is investigated through numerical means. To this end, the behavior of the membrane with temperature and humidity dependent material properties is simulated under temperature and humidity loading and unloading conditions. The stress-evolution during a simplified operating cycle is determined using finite element analysis for two clamping methods and two alignments of the bipolar plates. It is shown that compressive, plastic deformation occurs during the hygro-thermal loading, resulting in tensile residual stresses after unloading. These residual in-plane stresses in the …
Evolution Of Surface Morphology Of Thermo-Mechanically Cycled Nicocraly Bond Coats, J. Shi, Anette M. Karlsson, B. Baufeld, M. Bartsch
Evolution Of Surface Morphology Of Thermo-Mechanically Cycled Nicocraly Bond Coats, J. Shi, Anette M. Karlsson, B. Baufeld, M. Bartsch
Mechanical Engineering Faculty Publications
We investigate morphological surface instabilities on bond coat surfaces of thermal barrier coatings, induced due to thermo-mechanical loading. Experimental results of hollow circular cylindrical specimens, consisting of a directionally solidified superalloy (IN 100 DS) coated with a NiCoCrAlY bond coat, show that the morphological instabilities are strongly dependent on the load conditions. In particular, the morphological instabilities develop during thermal cycling with a thermal gradient over the cylinder wall, whereas the surface remains smooth for thermal cyclic conditions without a gradient. Furthermore, if a cyclic, axial tensile force is applied (synchronized with the thermal cycling), the morphological instabilities become aligned …
An Initial Non-Equilibrium Porous-Media Model For Cfd Simulation Of Stirling Regenerators, Roy C. Tew, Terry Simon, David Gedeon, Mounir B. Ibrahim, Wei Rong
An Initial Non-Equilibrium Porous-Media Model For Cfd Simulation Of Stirling Regenerators, Roy C. Tew, Terry Simon, David Gedeon, Mounir B. Ibrahim, Wei Rong
Mechanical Engineering Faculty Publications
The objective of this paper is to define empirical parameters for an initial thermal non-equilibrium porous-media model for use in Computational Fluid Dynamics (CFD) codes for simulation of Stirling regenerators. The two codes currently used at Glenn Research Center for Stirling modeling are Fluent and CFD-ACE. The codes’ porous-media models are equilibrium models, which assume solid matrix and fluid are in thermal equilibrium. This is believed to be a poor assumption for Stirling regenerators; Stirling 1–D regenerator models, used in Stirling design, use non-equilibrium regenerator models and suggest regenerator matrix and gas average temperatures can differ by several degrees at …