Internal Energy Transfer and Dissociation Model Development using Accelerated First-Principles Simulations of Hypersonic Flow Features

2013 ◽  
Author(s):  
Thomas E. Schwartzentruber
Keyword(s):  
Energy Transfer ◽  
Hypersonic Flow ◽  
Internal Energy ◽  
First Principles ◽  
Model Development ◽  
Flow Features ◽  
Dissociation Model

Quasiresonance:  Switching Internal Energy Transfer On and Off†

2005 ◽  
Vol 109 (50) ◽  
pp. 11578-11586 ◽  
Author(s):  
Antonia Ruiz ◽  
Eric J. Heller
Keyword(s):  
Energy Transfer ◽  
Internal Energy

scholarly journals Internal Energy Transfer in Dynamical Behavior of Slightly Curved Shear Deformable Microplates

2015 ◽  
Vol 11 (4) ◽  
Author(s):  
Mergen H. Ghayesh ◽  
Hamed Farokhi ◽  
Gursel Alici
Keyword(s):  
Energy Transfer ◽  
Internal Energy ◽  
Couple Stress Theory ◽  
Dynamical Behavior ◽  
Shear Deformation Theory ◽  
Initial Imperfection ◽  
Modal Interactions ◽  
Initial Curvature ◽  
Out Of Plane ◽  
Transfer Mechanisms

This paper investigates the internal energy transfer and modal interactions in the dynamical behavior of slightly curved microplates. Employing the third-order shear deformation theory, the microplate model is developed taking into account geometric nonlinearities as well as the modified couple stress theory; the initial curvature is modeled by an initial imperfection in the out-of-plane direction. The in-plane displacements and inertia are retained, and the coupled out-of-plane, rotational, and in-plane motion characteristics are analyzed. Specifically, continuous models are developed for kinetic and potential energies as well as damping and external works; these are balanced and reduced via Lagrange's equations along with an assumed-mode technique. The reduced-order model is then solved numerically by means of a continuation technique; stability analysis is performed by means of the Floquet theory. The possibility of the occurrence of modal interactions and internal energy transfers is verified via a linear analysis on different natural frequencies of the system. The nonlinear resonant response of the system is obtained for the cases with internal energy transfer, and energy transfer mechanisms are analyzed; as we shall see, the presence of an initial curvature affects the system dynamics substantially. The importance of taking into account small-size effects is also shown by discovering this fact that both the linear and nonlinear internal energy transfer mechanisms are shifted substantially if this effect is ignored.

Internal‐Energy‐Transfer Efficiencies in Eu3+ and Tb3+ Chelates Using Excitation to Selected Ion Levels

1966 ◽  
Vol 45 (7) ◽  
pp. 2410-2418 ◽  
Author(s):  
William R. Dawson ◽  
John L. Kropp ◽  
Maurice W. Windsor
Keyword(s):  
Energy Transfer ◽  
Internal Energy

Visualization and Validation of Ejector Flow Field With Computational and First-Principles Analysis

2015 ◽  
Vol 137 (5) ◽  
Author(s):  
Adrienne B. Little ◽  
Yann Bartosiewicz ◽  
Srinivas Garimella
Keyword(s):  
Flow Field ◽  
First Principles ◽  
Large Scale ◽  
Turbulence Models ◽  
Ideal Gas ◽  
Analytical Models ◽  
Local Flow ◽  
Flow Features ◽  
Flow Phenomena ◽  
Air Ejector

Passive, heat actuated ejector pumps offer simple and energy-efficient options for a variety of end uses with no electrical input or moving parts. In an effort to obtain insights into ejector flow phenomena and to evaluate the effectiveness of commonly used computational and analytical tools in predicting these conditions, this study presents a set of shadowgraph images of flow inside a large-scale air ejector and compares them to both computational and first-principles-based analytical models of the same flow. The computational simulations used for comparison apply k-ε renormalization group (RNG) and k-ω shear stress transport (SST) turbulence models to two-dimensional (2D), locally refined rectangular meshes for ideal gas air flow. A complementary analytical model is constructed from first principles to approximate the ejector flow field. Results show that on-design ejector operation is predicted with reasonable accuracy, but accuracy with the same models is not adequate at off-design conditions. Exploration of local flow features shows that the k-ω SST model predicts the location of flow features, as well as global inlet mass flow rates, with greater accuracy. The first-principles model demonstrates a method for resolving the ejector flow field from relatively little visual data and shows the evolving importance of mixing, momentum, and heat exchange with the suction flow with distance from the motive nozzle exit. Such detailed global and local exploration of ejector flow helps guide the selection of appropriate turbulence models for future ejector design purposes, predicts locations of important flow phenomena, and allows for more efficient ejector design and operation.

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