Effect of temperature dependent properties on thermal radiative loading of planar surfaces with distinct heaters

The accumulation of cyclic plasticity in bond coat (BC) is a key factor controlling the displacement instability of the thermally grown oxide (TGO) in thermal barrier systems. The cyclic plasticity is affected by the component material properties, which vary observably with the service temperature. A numerical model with the behavior of creep and thermal growth in TGO under thermal cycling is used to explore the effect of temperature-dependent properties on cyclic plasticity in BC. The influence of temperature-dependent Young's modulus of thermal barrier coating (TBC), TGO, BC and substrate, thermal expansion coefficient of TBC, BC and substrate, and the yield strength of BC on cyclic plasticity in BC is discussed respectively.

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Behavior of a Compressible Magnetorheological Fluid Damper at High Temperatures

ASME 2011 Conference on Smart Materials, Adaptive Structures and Intelligent Systems, Volume 1 ◽

10.1115/smasis2011-5127 ◽

2011 ◽

Cited By ~ 1

Author(s):

Micheal McKee ◽

Xiaojie Wang ◽

Faramarz Gordaninejad

Keyword(s):

Theoretical Model ◽

Bulk Modulus ◽

Yield Stress ◽

Magnetorheological Fluid ◽

Effect Of Temperature ◽

Temperature Dependent ◽

Bingham Plastic ◽

Shear Yield ◽

Fluid Dampers ◽

Temperature Dependent Properties

This study focuses on the effect of temperature on the performance of compressible magnetorheological fluid dampers (CMRDs). In addition to change of properties in the presence of a magnetic field, magnetorheological fluids (MRFs) are temperature-dependent materials that their compressibility and rheological properties change with temperature, as well. A theoretical model that incorporates the temperature-dependent properties of MRF is developed to predict the behavior of a CMRD. An experimental study is also conducted using an annular flow CMRD with varying temperatures, motion frequencies, and magnetic fields. The experimental results are used to verify the theoretical model. The effect of temperature on the MRF properties, such as, the bulk modulus, yield stress and viscosity, are explored. It is found that the shear yield stress of the MRF remains unchanged within the testing range while both the plastic viscosity, using the Bingham plastic model, and the bulk modulus of the MRF decrease as temperature increases. In addition, it is observed that both the stiffness and the energy dissipation decrease with an increase in temperature.

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Effect of Temperature Dependent Properties on the Applicability of the Heat Conduction Equations for Rapid Heat Deposition Applications

Volume 1A: 36th Computers and Information in Engineering Conference ◽

10.1115/detc2016-59631 ◽

2016 ◽

Cited By ~ 2

Author(s):

John G. Michopoulos ◽

Andrew Birnbaum ◽

Athanasios P. Iliopoulos

Keyword(s):

Differential Equation ◽

Thermal Properties ◽

Heat Conduction ◽

Effect Of Temperature ◽

Temperature Dependent ◽

Proper Form ◽

Heat Deposition ◽

Hyperbolic Form ◽

Parabolic Form ◽

Temperature Dependent Properties

Despite significant efforts examining the suitability of the proper form of the heat transfer partial differential equation (PDE) as a function of the time scale of interest (e.g. seconds, picoseconds, femtoseconds, etc.), very little work has been done to investigate the millisecond-microsecond regime. This paper examines the differences between the parabolic and one of the hyber-bolic forms of the heat conduction PDE that govern the thermal energy conservation on these intermediate timescales. Emphasis is given to the types of problems where relatively fast heat flux deposition is realized. Specifically, the classical parabolic form is contrasted against the lesser known Cattaneo-Vernotte hyperbolic form. A comparative study of the behavior of these forms over various pulsed conditions are applied at the center of a rectangular plate. Further emphasis is given to the variability of the solutions subject to constant or temperature-dependent thermal properties. Additionally, two materials, Al-6061 and refractory Nb1Zr, with widely varying thermal properties, were investigated.

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