Reduced-Order Modeling of Conjugate Heat Transfer Processes

2016 ◽  
Vol 138 (5) ◽  
Author(s):  
Trevor J. Blanc ◽  
Matthew R. Jones ◽  
Steven E. Gorrell
Keyword(s):  
Heat Transfer ◽  
Conjugate Heat Transfer ◽  
Reduced Order Modeling ◽  
Order Model ◽  
Linear Combinations ◽  
Reduced Order ◽  
Transfer Processes ◽  
Modeling Techniques ◽  
Expansion Coefficients ◽  
Basis Vectors

This paper describes the application of reduced-order modeling techniques in the simulation of conjugate heat transfer processes. In a reduced-order model (ROM), the dominate features of a system are represented using a limited number of orthonormal basis vectors, which are extracted from a database containing descriptions of the system. Interpolating methods are then used to calculate expansion coefficients that allow representation of the system as linear combinations of the basis vectors. Evidence of the accuracy and computational savings achieved using the reduced-order modeling technique is presented in order to demonstrate its benefits in simulating conjugate heat transfer processes.

Reduced Order Modeling and Compression of Data Produced by Simulations of Transient and Periodic Heat Transfer Processes

2013 ◽  
Author(s):  
Trevor J. Blanc ◽  
Matthew R. Jones ◽  
Steven E. Gorrell ◽  
Earl P. N. Duque
Keyword(s):  
Heat Transfer ◽  
Reduced Order Modeling ◽  
Computationally Efficient ◽  
Reduced Order ◽  
Thermal Transients ◽  
Complex Dynamic Systems ◽  
Modeling Techniques ◽  
Small Set ◽  
Periodic Heat ◽  
Value Decomposition

Reduced Order Modeling may be used to obtain compact and computationally efficient representations of complex dynamic systems. The objective of this paper is to demonstrate the application of reduced order modeling techniques to systems undergoing thermal transients. In this paper, a reduced order model is defined as a spectral method in which the dominant features of a spatially and temporally varying temperature profile are represented using a relatively small set of basis vectors. Although various approaches are possible, reduced order modeling generally relies on the use the singular value decomposition of a matrix containing representative data to generate an orthonormal basis for the process to be modeled. The results presented in this paper illustrate reduced order modeling of periodic and transient heat transfer in an axisymmetric system. Measures demonstrating the accuracy and computational savings associated with the use of reduced order modeling are presented.

Lattice Boltzmann Flow Simulations With Applications of Reduced Order Modeling Techniques.

2014 ◽  
Author(s):  
Donald L. Brown ◽  
Jun Li ◽  
Victor M. Calo ◽  
Mehdi Ghommem ◽  
Yalchin Efendiev
Keyword(s):  
Lattice Boltzmann ◽  
Reduced Order Modeling ◽  
Reduced Order ◽  
Flow Simulations ◽  
Modeling Techniques

Data-driven reduced order modeling based on tensor decompositions and its application to air-wall heat transfer in buildings

SeMA Journal ◽  
2021 ◽  
Author(s):  
M. Azaïez ◽  
T. Chacón Rebollo ◽  
M. Gómez Mármol ◽  
E. Perracchione ◽  
A. Rincón Casado ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Reduced Order Modeling ◽  
Data Driven ◽  
Wall Heat Transfer ◽  
Reduced Order ◽  
Tensor Decompositions

Numerical Investigation of Heat Transfer in the Wake of a Single Highly Confined Bubble in a Horizontal Minichannel

2018 ◽  
Author(s):  
John R. Willard ◽  
D. Keith Hollingsworth
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Enhancement ◽  
Numerical Investigation ◽  
Channel Flow ◽  
Heat Generation ◽  
Reduced Order Model ◽  
Two Dimensional ◽  
Transfer Enhancement ◽  
Order Model ◽  
Reduced Order

Confined bubbly flows in millimeter-scale channels produce significant heat transfer enhancement when compared to single-phase flows. Experimental studies support the hypothesis that the enhancement is driven by a convective phenomenon in the liquid phase as opposed to sourcing from microlayer evaporation or active nucleation. A numerical investigation of flow structure and heat transfer produced by a single bubble moving through a millimeter-scale channel was performed in order to document the details of this convective mechanism. The simulation includes thermal boundary conditions emulating those of the experiments, and phase change was omitted in order to focus only on the convective mechanism. The channel is horizontal with a uniform-heat-generation upper wall and an adiabatic lower surface. A Lagrangian framework was adopted such that the computational domain surrounds the bubble and moves at the nominal bubble speed. The liquid around the bubble moves as a low-Reynolds-number unsteady laminar flow. The volume-of-fluid method was used to track the liquid/gas interface. This paper reviews the central results of this simulation regarding wake heat transfer. It then compares the findings regarding Nusselt number enhancement to a reduced-order model on a two-dimensional domain in the wake of the bubble. The model solves the advective-diffusion equation assuming a velocity field consistent with fully developed channel flow in the absence of the bubble. The response of the uniform-heat-generation upper wall is included. The model assumes a temperature profile directly behind the bubble which represents a well-mixed region produced by the passage of the bubble. The significant wake heat transfer enhancement and its decay with distance from the bubble documented by the simulation were captured by the reduced-order model. However, the channel surface temperature recovered in a much shorter distance in the simulation compared to the reduced-order model. This difference is attributed to the omission of transverse conduction within the heated surface in the two-dimensional model. Beyond approximately one bubble diameter into the bubble wake, the complex flow structures are replaced by the momentum field of the precursor channel flow. However, the properties and thickness of the heated upper channel wall govern the heat transfer for many bubble diameters behind the bubble.

Modeling Constrained Layer Frictional Interfaces With Discontinuous Basis Functions

2011 ◽  
Author(s):  
M. R. Brake ◽  
M. J. Starr ◽  
D. J. Segalman
Keyword(s):  
Continuous System ◽  
Reduced Order Modeling ◽  
Basis Functions ◽  
Mode Shapes ◽  
Symmetric Model ◽  
Reduced Order ◽  
Linear Mode ◽  
System A ◽  
Modeling Techniques ◽  
A New Technique

Constrained layer frictional interfaces, such as joints, are prevalent in engineering applications. Because these interfaces are often used in built-up structures, reduced order modeling techniques are utilized for developing simulations of them. One limitation of the existing reduced order modeling techniques, though, is the loss of the local kinematics due to regularization of the frictional interfaces. This paper aims to avoid the use of regularization in the modeling of constrained layer frictional interfaces by utilizing a new technique, the discontinuous basis function method. This method supplements the linear mode shapes of the system with a series of discontinuous basis functions that are used to account for nonlinear forces acting on the system. A symmetric, constrained layer frictional interface is modeled as a continuous system connected to two rigid planes by a series of Iwan elements. This symmetric model is used to test the hypothesis that symmetric problems are not subjected to the range of variability seen in physical structures, which have non-uniform pressure and friction distributions. Insights from solving the symmetric problem are used to consider the case where a non-uniform distribution of friction and pressure exists.

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