Thermal Analysis of Some Subterrene Penetrators

1976 ◽  
Vol 98 (3) ◽  
pp. 485-490 ◽  
Author(s):  
H. N. Fisher
Keyword(s):  
Power Generation ◽  
Thermal Analysis ◽  
Heat Conduction ◽  
Material Properties ◽  
Thermal Analyses ◽  
Heat Pipes ◽  
Rock Properties ◽  
Internal Temperature ◽  
Temperature Dependent ◽  
Advance Rate

Various types of rock melting drills have been designed at Los Alamos. These have included density consolidating penetrators up to 90 mm in diameter of varying configurations. A number of these consolidators have been tested in loams, alluvium, and tuff. Extruders up to 87 mm in diameter designed for an improved advance rate have been used in alluvium and basalt. The results of thermal analyses of some of these existing penetrators under conditions of constant advance rate in tuff, alluvium, and basalt are presented. The basic finite element heat conduction code (AYER) used in the calculations is briefly reviewed along with the methods of including radiation, temperature dependent material properties, and power generation. The internal temperature distribution, power requirements, and possible advance rates are determined for various consolidating and extruding penetrators. The effects of rock properties, penetrator configuration, and thermal limitations on the advance rate are considered. Heater designs and the use of heat pipes in specific designs are discussed. A comparison with experimental test data is made where possible.

A Feasibility Investigation on Improving Structural Integrity of Thermoelectric Modules With Varying Geometry

2012 ◽  
Author(s):  
Ugur Erturun ◽  
Karla Mossi
Keyword(s):  
Power Generation ◽  
Material Properties ◽  
Thermal Stresses ◽  
Structural Integrity ◽  
Temperature Dependent ◽  
Thermoelectric Modules ◽  
Geometry Model ◽  
Von Mises ◽  
Von Mises Stresses ◽  
Ansys Workbench

This study investigates the feasibility of improving the structural integrity of thermoelectric modules (TEMs) with varying geometry. For this purpose, six different TEM models with various thermoelectric leg geometries were designed and modeled in order to perform a thermal stress FEA using ANSYS Workbench. Temperature dependent material properties were used since some properties such as coefficients of thermal expansion change with temperature. Significant decrease in thermal stresses and leg deformations were observed with some models. Particularly, the cylindrical TE leg geometry model has approximately 54% lower Von Mises stresses (294MPa) and 13% lower TE leg deformations (3.9μm) than those of the typical TE leg geometry model (635MPa and 4.5μm). Power generation analyses of the models were performed to evaluate the effect of new TE leg geometries on the performance. TEM model with cylindrical TE leg geometry has the highest power generation (29.3mW) among all the models.

Numerical Analysis of the Effect of Phase Transformation on Residual Stresses in an Autogenous Beam Edge Weld

2013 ◽  
Vol 768-769 ◽  
pp. 652-659
Author(s):  
Martina M. Joosten
Keyword(s):  
Thermal Analysis ◽  
Numerical Analysis ◽  
Heat Source ◽  
Residual Stresses ◽  
Phase Transformations ◽  
Material Properties ◽  
Base Material ◽  
Temperature Dependent ◽  
Thin Beam ◽  
Beam Edge

This paper presents the numerical analysis of phase proportions and residual stresses in an autogenous beam edge weld. The thin beam was welded running a heat source along its longer edge using a TIG process. There is no addition of any material so the focus of modelling the process could be concentrated on the thermal analysis and the phase transformations. Temperature dependent material properties and a continuous cooling transformation (CCT) diagram of the base material were provided. The simulations took into account metallurgical effects and used a Goldak-type heat source. Simulations with and without phase transformations were carried out, in order to analyse the effect on the predicted residual stress.

scholarly journals Determination of the Temperature-Dependent Thermal Material Properties in the Cooling Process of Steel Plates

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Dimitri Rothermel ◽  
Thomas Schuster ◽  
Roland Schorr ◽  
Martin Peglow
Keyword(s):  
Heat Conduction ◽  
Material Properties ◽  
Nonlinear Partial Differential Equation ◽  
Steel Plates ◽  
Temperature Evolution ◽  
Cooling Process ◽  
Temperature Dependent ◽  
Material Parameters ◽  
Thermophysical Characterization

Accelerated cooling (ACC) is a key technology in producing thermomechanically controlled processed (TMCP) steel plates. In a TMCP process, hot plates are subjected to a strong cooling resulting in a complex microstructure leading to increased strength and fracture toughness. The microstructure, residual stresses, and flatness deformations are strongly affected by the temperature evolution during the cooling process. Therefore, the full control (quantification) of the temperature evolution is essential regarding plate design and processing. It can only be achieved by a thermophysical characterization of the material and the cooling system. In this paper, the focus is on the thermophysical characterization of the material properties which govern the heat conduction behavior inside of the plates. Mathematically, this work considers a specific inverse heat conduction problem (IHCP) utilizing inner temperature measurements. The temperature evolution of a heated steel plate passing through the cooling device is modeled by a 1D nonlinear partial differential equation with temperature-dependent material parameters which describe the characteristics of the underlying material. Usually, the material parameters considered in IHCPs are often defined as functions of the space and/or time variables only. Since the measured data (the effect) and the unknown material properties (the cause) depend on temperature, the cause-to-effect relationship cannot be decoupled. Hence, the parameter-to-solution operator can only be defined implicitly. By proposing a parametrization approach via piecewise interpolation, this problem can be resolved. Lastly, using simulated measurement data, the presentation of the numerical procedure shows the ability to identify the material parameters (up to some canonical ambiguity) without any a priori information.

Sign in / Sign up

Export Citation Format

Share Document