Heat Transfer Through Small Moveable Gas Gaps in a Multi-Body System Using the ANSYS Finite Element Software

2013 ◽  
Author(s):  
Joel L. McDuffee
Keyword(s):  
Heat Transfer ◽  
Finite Element ◽  
Thermal Contact ◽  
National Laboratory ◽  
Oak Ridge ◽  
Finite Element Software ◽  
Advanced Fuels ◽  
Accurate Temperature ◽  
Multi Body ◽  
Helium Neon

The Thermal Hydraulics and Irradiation Engineering (THIE) Group at Oak Ridge National Laboratory (ORNL) designs and builds capsules in which to irradiate advanced fuels and materials that are typically inserted into ORNL’s High Flux Isotope Reactor. Experiments are designed to achieve a target temperature that ranges from 250°C to 1200°C. Most capsules do not have active temperature measurement or control, which puts an imperative on accurate temperature simulation. Temperature control in these capsules is accomplished by designing specific gaps between adjacent parts and filling the capsules with an inert gas: helium, neon, or argon. Most any finite element solver will do an excellent job estimating temperatures within individual parts, but the simulation challenge for these complex, multi-body systems is to accurately predict the heat transfer through contact surfaces or interstitial gas gaps. The gas gaps are on the order of 150 μm, so accurate simulation must include thermal expansion of the adjacent parts, the thermal jump effect on the part surfaces, and the possibility the parts will touch or break contact during expansion. This paper will discuss the limitations in thermal contact modeling in finite element modelers and the algorithms the THIE Group uses to overcome these limitations.

Finite Element Analysis about the Influence that High-Speed Motorized Spindle Spindle System Material has on its Temperature Field

2013 ◽  
Vol 712-715 ◽  
pp. 1209-1212 ◽  
Author(s):  
Ke Zhang ◽  
Xiang Nan Ma ◽  
Li Xiu Zhang ◽  
Wen Da Yu ◽  
Yu Hou Wu
Keyword(s):  
Heat Transfer ◽  
Finite Element ◽  
Temperature Field ◽  
Heat Transfer Rate ◽  
Transfer Rate ◽  
High Speed ◽  
Ceramic Materials ◽  
Motorized Spindle ◽  
Element Analysis ◽  
Finite Element Software

The article has analyzed the changes of temperature of different materials of the spindle, and considered 170SD30 Ceramic Motorized Spindle and the same model Metal Motorized Spindle as the research objects, analyzed the inside heat source and heat transfer mechanism of the high-speed motorized spindle; used finite element software to set up the model of the motorized spindle, and did simulation and analysis. Verified by simulation, heat transfer rate of ceramic materials is slower than the metallic materials, in actual operation of the process, due to different materials have different heat transfer rate, so the temperature distribution of the different materials of motorized spindle are different. This conclusion provides the basis to solve motorized spindle temperature field distribution.

ORNL Evaluation of Safety Cases for Two Belgian Reactor Pressure Vessels Containing Quasi-Laminar Defects

2017 ◽  
Author(s):  
Hilda B. Klasky ◽  
B. Richard Bass ◽  
Terry L. Dickson ◽  
Sarma B. Gorti ◽  
Randy K. Nanstad ◽  
...  
Keyword(s):  
New York ◽  
Finite Element ◽  
Structural Integrity ◽  
National Laboratory ◽  
Relevant Literature ◽  
Pressure Vessels ◽  
Oak Ridge ◽  
Safety Margins ◽  
Safety Cases ◽  
Reactor Pressure

The Oak Ridge National Laboratory (ORNL) performed a detailed technical review of the 2015 Electrabel (EBL) Safety Cases prepared for the Belgium reactor pressure vessels (RPVs) at Doel 3 and Tihange 2 (D3/T2). The Federal Agency for Nuclear Control (FANC) in Belgium commissioned ORNL to provide a thorough assessment of the existing safety margins against cracking of the RPVs due to the presence of almost laminar flaws found in each RPV. Initial efforts focused on surveying relevant literature that provided necessary background knowledge on the issues related to the quasi-laminar flaws observed in D3/T2 reactors. Next, ORNL proceeded to develop an independent quantitative assessment of the entire flaw population in the two Belgian reactors according to the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code, Section XI, Appendix G, “Fracture Toughness Criteria for Protection Against Failure,” New York (both 1992 and 2004 versions). That screening assessment of the EBL-characterized flaws in D3/T2 used ORNL tools, methodologies, and the ASME Code Case N-848, “Alternative Characterization Rules for Quasi-Laminar Flaws”. Results and conclusions derived from comparisons of the ORNL flaw acceptance assessments of D3/T2 with those from the 2015 EBL Safety Cases are presented in the paper. The ORNL screening analyses identified fewer flaws than EBL that were not compliant with the ASME Section XI (1992) criterion; the EBL criterion imposed additional conservatisms not included in ASME Section XI. Furthermore, ORNL’s application of the updated ASME Section XI (2004) criterion produced only four non-compliant flaws, all due to design-basis loss-of-coolant loading transients. Among the latter, only one flaw remained non-compliant when analyzed using the warm-prestress (WPS) cleavage fracture model typically applied in USA flaw assessments. ORNL’s independent refined analysis of that flaw (#1660, which was also non-compliant in the EBL screening assessments) rendered it compliant when modeled as a more realistic individual quasi-laminar flaw using a 3-dimensional XFEM (eXtended Finite Element Method) approach available in the ABAQUS© finite element code. Taken as a whole, the ORNL-specific results and conclusions confirmed the structural integrity of Doel 3 and Tihange 2 under all design transients with ample margin in the presence of the 16,196 detected flaws.

Experimental Program for Investigating the Influence of Cladding Defects on Burst Pressure

2006 ◽  
Author(s):  
Shengjun (Sean) Yin ◽  
B. Richard Bass ◽  
Wallace J. McAfee ◽  
Paul T. Williams
Keyword(s):  
Finite Element ◽  
National Laboratory ◽  
Maximum Load ◽  
Plastic Instability ◽  
Experimental Program ◽  
Finite Element Models ◽  
Ductile Tearing ◽  
Oak Ridge ◽  
Clad Layer ◽  
Good Agreement

An experimental program was conducted by the Heavy-Section Steel Technology Program at the Oak Ridge National Laboratory (ORNL) to evaluate the structural significance of defects found in the unbacked cladding of the Davis-Besse vessel head. ORNL conducted total 13 clad burst tests with unflawed/flawed specimens. Failure pressure data from those tests indicated a high degree of repeatability for the tests performed in the clad burst program. Unflawed clad burst specimens failed around the full perimeter of the disk from plastic instability; an analytical model for plastic collapse was shown to adequately predict those results. The flawed specimens tested in the program failed by ductile tearing of the notch defect through the clad layer. Analytical interpretations that utilized 3-D finite element models of the clad burst specimens were performed for all tests. Fractographic studies were performed on failed defects in the flawed burst specimens to verify the ductile mode of failure. Comparisons of computed results from 3-D finite element models with measured gage displacement data (i.e., center-point deflection and CMOD) indicated reasonably good agreement up to the region of instability. For tests instrumented with the CMOD gage, good agreement between calculated and measured CMOD data up to the onset of instability implies that ductile tearing initiated near the maximum load and (with a small increase in load) rapidly progressed through the clad layer to produce failure of the specimen.

Modeling the Residual Stress in Woven Thermoset Composites Parts for Aerospace Applications Using Finite Element Methods

2015 ◽  
Vol 1099 ◽  
pp. 32-36 ◽  
Author(s):  
Yasir Nawab ◽  
Chung Hae Park ◽  
Abdelghani Saouab ◽  
Romain Agogué ◽  
Pierre Beauchêne
Keyword(s):  
Heat Transfer ◽  
Finite Element ◽  
Epoxy Composite ◽  
Cure Kinetics ◽  
Chemical Shrinkage ◽  
Significant Issue ◽  
Precise Information ◽  
Thermoset Composites ◽  
Finite Element Software ◽  
Aerospace Applications

Process induced residual stresses in thermoset composite parts is one of significant issue faced by the industry. Its Modelling is a coupled multiphysics phenomena. Precise information about the chemical shrinkage, thermal expansion coefficient, cure kinetics, heat transfer and constitutive equation are required for an accurate simulation. In this article, spring-in angle induced in woven carbon/epoxy composite bracket is modelled by solving the thermo-kinetics and thermo-mechanics coupling simultaneously in a commercial finite element software. The obtained values of spring-in angle using numerical simulation are compared with those found in the literature and both are found in agreement.

Finite Element-Based Analysis of Bio-Heat Transfer in Human Skin Burns and Afterwards

2020 ◽  
pp. 2041010
Author(s):  
Abul Mukid Md. Mukaddes ◽  
Ryuji Shioya ◽  
Masao Ogino ◽  
Dipon Roy ◽  
Rezwan Jaher
Keyword(s):  
Heat Transfer ◽  
Finite Element ◽  
Human Skin ◽  
Burn Injuries ◽  
Heat Transfer Analysis ◽  
Skin Damage ◽  
Skin Burn ◽  
Burn Treatment ◽  
Thermal Burn ◽  
Finite Element Software

This research was conducted to develop the three-dimensional (3D) finite element model of human skin for bio-heat transfer analysis. The skin burn was analyzed using Penne’s bio-heat equation, which has been adopted in many commercial finite element software. Burn injuries mostly occur due to heat transfer from hot object, hot liquids, cooking flames, and sometimes due to exposure to chemicals, electricity, and ionizing radiation. Depending upon the condition and duration of exposing, thermal burn may cause severe skin damage. The burn effect on human skin under the contact with a hot object or hot fluid was analyzed in this paper. The burn intensity in terms of degrees of burn was measured with different burning conditions and their corresponding time was graphically shown. Using the temperature profile obtained from the analysis, various methods of burn treatment were evaluated and compared. The results from this analysis will help to understand human skin burn under different burning conditions and treatment of different burn injuries.

Numerical Simulation for Thick-Walled Hollow Axle during Cross Wedge Rolling

2011 ◽  
Vol 337 ◽  
pp. 270-273 ◽  
Author(s):  
Yang Jiang ◽  
Bao Yu Wang ◽  
Zheng Huan Hu ◽  
Jian Guo Lin
Keyword(s):  
Heat Transfer ◽  
Numerical Simulation ◽  
Finite Element ◽  
Numerical Model ◽  
Rolling Process ◽  
Cross Wedge Rolling ◽  
Finite Element Software ◽  
Temperature Distributions ◽  
Simulation Results ◽  
Deform 3D

The paper investigates a process of cross wedged rolling (CWR) for manufacturing thick-walled hollow axles. A finite element numerical model coupled deformation and heat transfer of CWR is established using commercial finite element software DEFORM-3D. The rolling process of hollow axle during CWR is simulated successfully. The stress, strain and temperature distributions of workpiece are obtained and analyzed. The simulation results show that forming thick-walled hollow axles through CWR is feasible.

Simulation and Study on Ride Comfort of Articulated Dump Truck Based on Rigid-Flex Coupling

2014 ◽  
Vol 494-495 ◽  
pp. 55-58
Author(s):  
Jie Guo
Keyword(s):  
Finite Element ◽  
Ride Comfort ◽  
Dynamic Theory ◽  
Dynamics Simulation ◽  
Dump Truck ◽  
Body System ◽  
Finite Element Software ◽  
Body Dynamics ◽  
Set Up ◽  
Multi Body

For the poor ride comfort performance of the articulated dump truck, the dynamic model of ADT was built and its dynamic characteristics were also studied through finite element and multi-body system dynamic theory. According to the modal neutral file generated by finite element software with the flexible processing, the flexible coupling virtual prototyping model was set up for the multi-body dynamics simulation in ADAMS to obtain and analyze the data about the ADT ride comfort. This paper provided references for the design, redesign and optimization of the ADT.

scholarly journals Thermal Predictions of the AGR-3/4 Experiment With Time Varying Gas Gaps

2014 ◽  
Author(s):  
Grant L. Hawkes ◽  
James W. Sterbentz ◽  
John T. Maki
Keyword(s):  
Heat Transfer ◽  
Thermal Analysis ◽  
Finite Element ◽  
Fast Neutron ◽  
Neutron Fluence ◽  
National Laboratory ◽  
Surface Radiation ◽  
Time Varying ◽  
Fuel Component ◽  
Enriched Uranium

A thermal analysis was performed for the Advanced Gas Reactor test experiment (AGR-3/4) with time varying gas gaps. The experiment was irradiated at the Advanced Test Reactor (ATR) at the Idaho National Laboratory (INL). Several fuel irradiation experiments are planned for the AGR Fuel Development and Qualification Program which supports the development of the Very-High-Temperature gas-cooled Reactor (VHTR) under the Next-Generation Nuclear Plant (NGNP) project. AGR-3/4 combines two tests in a series of planned AGR experiments to test tri-structural-isotropic (TRISO)-coated, low-enriched uranium oxy-carbide fuel. The AGR-3/4 test was designed primarily to assess fission product transport through various graphite materials. The AGR-3/4 test irradiation in the ATR started in December 2011 and finished in April 2014. Forty-eight (48) TRISO fueled compacts were inserted into twelve separate capsules for the experiment (four compacts per capsule). The purpose of this analysis was to calculate the temperatures of each compact and graphite layer to obtain daily average temperatures using time (fast neutron fluence) varying gas gaps and to compare with experimentally measured thermocouple data. Previous experimental data was used for the graphite shrinkage versus fast neutron fluence. Heat rates were input from a detailed physics analysis using the Monte Carlo N-Particle (MCNP) code for each day during the experiment. Individual heat rates for each non-fuel component were input as well. A steady-state thermal analysis was performed for each daily calculation. A finite element model was created for each capsule using the commercial finite element heat transfer and stress analysis package ABAQUS. The fission and neutron gamma heat rates were calculated with the nuclear physics code MCNP. ATR outer shim control cylinders and neck shim rods along with driver fuel power and fuel depletion were incorporated into the daily physics heat rate calculations. Compact and graphite thermal conductivity were input as a function of temperature and neutron fluence with the field variable option in ABAQUS. Surface-to-surface radiation heat transfer along with conduction heat transfer through the gas mixture of helium-neon (used for temperature control) was used in these models. Model results are compared to thermocouple data taken during the experiment.

Ammonia Condensation on Smooth and Fluted Aluminum Tubes

1982 ◽  
Vol 104 (1) ◽  
pp. 9-14 ◽  
Author(s):  
N. Domingo ◽  
J. W. Michel
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Tube Bundle ◽  
National Laboratory ◽  
Argonne National Laboratory ◽  
Smooth Tube ◽  
Transfer Coefficients ◽  
Oak Ridge ◽  
Aluminum Tubes ◽  
Overall Performance

Experiments relative to heat exchangers for ocean thermal energy conversion (OTEC) systems have been completed for ammonia condensing on the outside of four aluminum tubes of three types: a smooth tube, a single (external) fluted tube, and two double (internal/external) fluted tubes. Composite heat transfer coefficients (coefficients that include vapor-side plus wall resistance) are reported for a smooth tube condensing horizontally and at various tilt angles, and for a single-fluted tube condensing vertically. Overall heat transfer data are given for both double-fluted tubes. The primary conclusions from this study were as follows: (a) smooth tube condensing performance was maximum for the horizontal orientation, where, for a given heat flux, composite coefficients were 2.1 times vertical smooth tube (1.2 m long) values; (b) a vertically oriented, single-fluted tube gave the highest performance among the tubes studied with composite condensing coefficients, at a given heat flux, up to 5.2 times the vertical smooth tube values; (c) overall performance for a tube with inside and outside flutes was 25 percent greater than observed for a tube having identical outside flutes but a smooth inside surface; (d) overall performance was virtually unchanged for a double-fluted aluminum tube as the number of external flutes was reduced from 45 to 36; and (e) overall heat transfer results from Oak Ridge National Laboratory (ORNL) double-fluted, vertical, single-tube tests were in approximate agreement with vertical, double-fluted condenser tube bundle data obtained by the Argonne National Laboratory (ANL).

Numerical Simulation of Cr12MoV Steel during Quenching Process

2014 ◽  
Vol 989-994 ◽  
pp. 751-754
Author(s):  
Wei Zhang ◽  
Zhou De Qu ◽  
Xiao Hu Deng ◽  
Xing Wang Duan
Keyword(s):  
Heat Transfer ◽  
Numerical Simulation ◽  
Residual Stress ◽  
Finite Element ◽  
Heat Transfer Coefficient ◽  
Surface Heat ◽  
Finite Element Software ◽  
Quenching Process ◽  
Surface Heat Transfer Coefficient ◽  
Nonlinear Surface

The excessive residual stress induced by quenching in steels will easily result in distortion and failure of parts. In order to obtain the more suitable quenchant, quenching process of Cr12MoV steel with different mediums involving water and oil are simulated, respectively. In present paper, the influence of nonlinear surface heat transfer coefficient, thermodynamic parameters and latent heat are considered comprehensively. The distribution of temperature, microstructure, hardness and residual stress after quenching for Cr12MoV steel are simulated by DEFORM finite element software. According to the results mentioned above, the variations of each field of the steel are analyzed.

Sign in / Sign up

Export Citation Format

Share Document