Estimation of moving heat source for an instantaneous three-dimensional heat transfer system based on step-renewed Kalman filter

Abstract Understanding of heat transfer during steaming is important to optimize the processing of steamed bread and to produce desired qualities in the final product. Physicochemical changes occur during steaming of the dough which might be impacted upon by the heat transfer system. In this study, a mathematical model was developed to describe the heat transfer system in the bread being steaming throughout the heating process. The Forward Euler method was employed for solving the three-dimensional partial differential equation set for heat transfer to produce temperature profiles at a number of individual locations in the steamed bread during its steaming. All the comparisons between the model-predicted values and the experimental results produced root mean square error values ranged from 1.391 to 3.545 and R2 values of all greater than 0.93. Therefore, it is confirmed that the model has a good performance and can be used to predict temperature profiles in the bread during steaming.

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Elastocaloric Cooling: System Design, Simulation, and Realization

Volume 2: Mechanics and Behavior of Active Materials; Structural Health Monitoring; Bioinspired Smart Materials and Systems; Energy Harvesting; Emerging Technologies ◽

10.1115/smasis2018-7982 ◽

2018 ◽

Author(s):

Felix Welsch ◽

Susanne-Marie Kirsch ◽

Nicolas Michaelis ◽

Paul Motzki ◽

Marvin Schmidt ◽

...

Keyword(s):

Heat Transfer ◽

Heat Source ◽

System Design ◽

Cooling System ◽

Coefficient Of Performance ◽

Transfer System ◽

Vapor Compression ◽

Cooling Systems ◽

Elastocaloric Cooling ◽

Heat Transfer System

Elastocaloric cooling is a novel environment-friendly alternative to vapor compression-based cooling systems. This solid-state cooling technology uses NiTi shape memory alloys (SMAs) as cooling medium. SMAs are well known for lightweight actuator systems and biomedical applications, but in addition, these alloys exhibit excellent cooling properties. Due to the high latent heats activated by mechanical loading/unloading, large temperature changes can be generated in the material. Accompanied by a small required work input, this also leads to a high coefficient of performance superior to vapor compression-based systems. In order to access the potential of these alloys, the development of suitable thermodynamic cooling cycles and an efficient system design are required. This paper presents a model-based design process of an elastocaloric air-cooling device. The device is divided into two parts, a mechanical system for continuously loading and unloading of multiple SMA wire bundles by a rotary motor and a heat transfer system. The heat transfer system enables an efficient heat exchange between the heat source and the SMA wires as well as between the SMA wires and the environment. The device operates without any additional heat transfer medium and cools the heat source directly, which is an advantage in comparison to conventional cooling systems. The design of this complex device in an efficient manner requires a model approach, capable of predicting the system parameters cooling power, mechanical work and coefficient of performance under various operating conditions. The developed model consists of a computationally efficient, thermo-mechanically coupled and energy based SMA model, a model of the system kinematics and a heat transfer model. With this approach, the complete cooling system can be simulated, and the required number of SMA wires as well as the mechanical power can be predicted in order to meet the system requirements. Based on the simulation results a first prototype of the elastocaloric cooling system is realized.

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Constructal Design of Cooling Channel in Heat Transfer System by Utilizing Optimality of Branch Systems in Nature

Journal of Heat Transfer ◽

10.1115/1.2426357 ◽

2005 ◽

Vol 129 (3) ◽

pp. 245-255 ◽

Cited By ~ 33

Author(s):

Xiaohong Ding ◽

Koetsu Yamazaki

Keyword(s):

Heat Transfer ◽

Minimum Energy ◽

Three Dimensional ◽

Generation Process ◽

Transfer System ◽

Cooling Channel ◽

Nutrient Distribution ◽

Cooling Channels ◽

Nutrient Density ◽

Heat Transfer System

There are similarities between the morphology of branch systems in nature and the layout of cooling channel in heat transfer system in engineering. The branch systems in nature always grow in such a way that approximate global optimal performances can be achieved. By utilizing the optimality of branch systems in nature, an innovative layout design methodology of cooling channel in heat transfer system is suggested in this paper. The emergent process of branch systems in nature is reproduced according to their common growth mechanisms. Branches are grown under the control of a so-called nutrient density so as to make it possible for the distribution of branches to be dependent on the nutrient distribution. The growth of branches also satisfies the hydrodynamic conditions and the minimum energy loss principle. If the so-called nutrient density in the generation process of branch systems is referred to as the heat energy in a heat transfer system, the distribution of branches is responsible for the distribution of cooling channels. Having similar optimality of branch systems in nature, the constructed cooling channel can be designed flexibly and effectively in any shape of perfusion volume to be cooled adaptively to very complex thermal boundary conditions. The design problems of both a conductive cooling channel and a convective cooling channel are studied, and the layouts of two-dimensional and three-dimensional cooling channels are illustrated. The cooling performances of the designed heat transfer systems are discussed by the finite element method analysis and are compared with the results designed by other conventional design methods.

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Heat Transfer of a Smoldering Flammable Substrate. Part 1. Development of a Theoretical Model for the Heat Transfer of a Smoldering Substrate

Journal of Fire Sciences ◽

10.1177/073490419701500603 ◽

1997 ◽

Vol 15 (6) ◽

pp. 462-480 ◽

Cited By ~ 2

Author(s):

Sung-Chul Yi

Keyword(s):

Heat Transfer ◽

Theoretical Model ◽

Heat Source ◽

Three Dimensional ◽

Solid Substrate ◽

Moving Heat Source ◽

Fourier Equation

Part 1 of this two part paper describes the development of a theo retical model for the interaction of the moving heat source and a solid substrate when they are in contact. For purposes of the model the substrate is assumed to act as a continuum and the Fourier equation for transient, three-dimensional conduction is solved using Laplace and Fourier transformations. Unlike most previous models, this model shows the explicit relations between the properties of the heat source and those of the substrate. Since the size, shape and speed of the heat source impact the ignition of substrate, considerable attention is devoted to evaluating these parameters. Results are presented which show the effects of the size, shape and speed of the heat source of the substrate.

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