Multiphysics modeling of a micro-scale Stirling refrigeration system

Guo, Dongzhi; McGaughey, Alan J. H.; Gao, Jinsheng; Fedder, Gary K.; Lee, Minyoung; Yao, Shi‐Chune

doi:10.1016/j.ijthermalsci.2013.07.003

Cited by 14 publications

(4 citation statements)

References 22 publications

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“…However, when additional constraints are introduced, the optimal flow-path is typically more complex, and not necessarily a single connected path. One such constraint is the desired fluid-solid contact area, which plays a crucial role in various applications such as bio-sensors for detecting tumor cells [2], microfluidic devices for cell sorting [3][4][5][6][7], micro-channel heat sinks [8][9][10], and other microfluidic devices involving heat transfer and mass transportation/mixing mechanisms [11,12]. In these applications, a minimum fluid-solid contact area is critical for achieving desired performance and functionality.…”

Section: Introductionmentioning

confidence: 99%

TOMAS: Topology Optimization of Multiscale Fluid-Flow Devices using Variational Autoencoders and Super-Shapes

Padhy,

Suresh,

Chandrasekhar

2023

Preprint

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In this paper, we present a framework for multiscale topology optimization of fluid-flow devices. The objective is to minimize dissipated power, subject to a desired contact-area. The proposed strategy is to design optimal microstructures in individual finite element cells, while simultaneously optimizing the overall fluid flow. In particular, parameterized super-shapes are chosen here to represent microstructures since they exhibit a wide range of permeability and contact area. To avoid repeated homogenization, a finite set of these super-shapes are analyzed a priori, and a variational autoencoder (VAE) is trained on their fluid constitutive properties (permeability), contact area and shape parameters. The resulting differentiable latent space is integrated with a coordinate neural network to carry out a global multi-scale fluid flow optimization. The latent space enables the use of new microstructures that were not present in the original data-set. The proposed method is illustrated using numerous examples in 2D Overview of the proposed method: A dataset of shape parameters of super-shapes, contact areas, and homogenized permeability tensors is used to train a variational autoencoder (VAE). The resulting latent space is then used for global multiscale optimization of fluid flow.

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Section: Introductionmentioning

confidence: 99%

TOMAS: Topology Optimization of Multiscale Fluid-Flow Devices using Variational Autoencoders and Super-Shapes

Padhy,

Suresh,

Chandrasekhar

2023

Preprint

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“…Hence considering these different requirements, it is essential to have a cryocooler controller that provides a good set-point tracking as well as disturbance-rejection responses for the cryocooler cold-tip temperature. It is found that researchers have also carried outwork on dynamic simulation through mathematical modelling (Guo. D. et al 2013) (Zhang et al 2002) and on a scheme for stroke length control with robustness test on change of load assuming FOPDT transfer function model (Yang et al 1999).…”

Section: Introductionmentioning

confidence: 99%

Cold-Tip Temperature Control of Space-borne Satellite Stirling Cryocooler: Mathematical Modeling and Control Investigation

2018

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IR (Infra-Red) detectors are widely used in Space-borne remote sensing satellites. In order to achieve a high signal to noise ratio, the IR detectors need to be operated at cryogenic temperatures. Traditionally, the cryogenic cooling of these detectors is achieved using passive cooling techniques. However recent trend is to employ Stirlingcycle based miniaturized active cryocoolers. An accurate and stringent control of active cryocooler cold-tip temperature is essential to accomplish high signal & image quality from the IR detectors. This paper presents work on investigations and comparison of performance of proposed 2-DOF (2-Degrees-of-Freedom) versus traditional 1-DOF feedback-control structures for the control of cryocooler cold-tip temperature used in IR (Infra-Red) detectors of Space Satellites. Towards this, first-principle based control oriented mathematical model simulated in Matlab/Simulink is proposed to support such investigation and controller tuning. Open-loop (system) and closedloop (controls) simulation results are tuned & validated with the experimental data obtained from the Lab-scale testsetup of a commercial Stirlingcryocooler. The performance of 2-DOF feedback control structures are analyzed with the help of experiment results offering a better cold-tip temperature control performance.

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“…Recently, the fluid flow across a bank of micro-pillars has been demonstrated to be essential for many MEMS devices and systems, such as micro-scale heat exchangers, micro heat sinks, micro chemical reactors, micro bio-MEMS devices, and also the micro-regenerator in the refrigeration system [1][2][3][4][5]. Therefore, the knowledge of the flow characteristic across a bank of micro-pillars under various hydrodynamic conditions is critical for optimally designing these systems.…”

Section: Introductionmentioning

confidence: 99%

“…In addition, most of the studies focus on the flow in the dense pillar array. However, the sparse pillar array is frequently applied for the regenerator in the micro-refrigeration system [2,3]. The pin fin spacing effect on the friction factor at the micro-scale is to be determined.…”

Section: Introductionmentioning

confidence: 99%

Experimental investigation of laminar flow across short micro pin fin arrays

Guo

Gao

Santhanam

et al. 2014

J. Micromech. Microeng.

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The pressure drop and friction factor of gas flow across an array of circular silicon micro-pillars with different diameters fabricated by deep reactive ion etch (DRIE) process were investigated. The pitch-to-diameter ratio (1.5 < ST/d < 2.3) and the height-to-diameter aspect ratio (0.48 < H/d < 2.28) were found to affect the friction factor of the pillar array significantly. A new correlation, which considered the coupled effect of pillar spacing and aspect ratio, was proposed to predict the friction factor in a Reynolds number range of 1–100. Silicon pillars with large artificial roughness amplitudes were also fabricated, and the effect of the roughness was studied in the laminar flow region. The results demonstrated that the pressure drop and the friction factor were reduced significantly (more than 50%) for the pillar array with a large artificial roughness, which may be used to improve the cooling efficiency for the regenerator structures in micro-coolers.

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Multiphysics modeling of a micro-scale Stirling refrigeration system

Cited by 14 publications

References 22 publications

TOMAS: Topology Optimization of Multiscale Fluid-Flow Devices using Variational Autoencoders and Super-Shapes

TOMAS: Topology Optimization of Multiscale Fluid-Flow Devices using Variational Autoencoders and Super-Shapes

Cold-Tip Temperature Control of Space-borne Satellite Stirling Cryocooler: Mathematical Modeling and Control Investigation

Experimental investigation of laminar flow across short micro pin fin arrays

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