Study of the Temperature Field in Microchannels of a PDMS Chip With Embedded Local Heater Using Temperature-Dependent Fluorescent Dye

2005 ◽  
Author(s):  
Rachel Fu ◽  
Bo Xu ◽  
Dongqing Li
Keyword(s):  
Numerical Simulation ◽  
Temperature Field ◽  
Thermal Response ◽  
Microfluidic Devices ◽  
Fluorescent Dye ◽  
Temperature Dependent ◽  
Heating And Cooling ◽  
Liquid Samples ◽  
Temperature Levels ◽  
Pdms Chip

This paper presents a simple microheater design for microfluidic devices by embedding resistance wire into a PDMS chip, and the results of an experimental study of the thermal response of liquid samples in the PDMS chip with the embedded local heater. Temperature-dependent fluorescent dye was used to measure the temperature distribution within a microchannel heated by the local heater. Two heater configurations were built, tested, and compared with numerical simulation. Through comparing the performance of these two configurations, heating and cooling rates and uniformity of the temperature field were evaluated. Additionally, thermal cycling at two different temperature levels was achieved by controlling the power of the local heater.

scholarly journals Research on the End-Face Distribution of Rotational Molding Heating Gun Based on Numerical Simulation Method

Processes ◽  
2022 ◽  
Vol 10 (1) ◽  
pp. 97
Author(s):  
Yongchun Yan ◽  
Lixin Zhang ◽  
Xiao Ma ◽  
Huan Wang ◽  
Wendong Wang ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Temperature Field ◽  
Field Distribution ◽  
Thermal Response ◽  
Response Model ◽  
Wall Surface ◽  
Rotational Molding ◽  
Temperature Field Distribution ◽  
Fire Dynamics ◽  
Validation Experiment

The distribution of heating gun ends plays a decisive role in the sidewall properties of finished rotomolded products. To obtain the optimal distribution of the end face of a rotational molding heating gun, the temperature response of the end-face mold under heating gun heating was investigated, and an analysis method based on numerical simulation is proposed. The FDS (fire dynamics simulator) was used to construct a heating model of the heating gun, simulate and obtain a heatmap of the temperature field distribution of a heating gun of Φ30–70 mm, and determine the optimal diameter and heating distance of the heating gun. ANSYS was used to establish the thermal response model of the heat-affected mold, which was combined with the mold structure and thermophysical properties of steel. A temperature field distribution on the inner wall surface of Φ30, Φ50, and Φ70 mm heating guns when heating at each diameter of the end face was obtained and the distribution position of the end face of each diameter heating gun was determined. ANSYS was used to establish the thermal response model of the end-face mold and obtain the temperature field distribution of the inner wall surface of the end-face mold. The size of the heat-affected area of each diameter heating gun was combined, the end-face heating gun distribution was optimized, and the optimal heating gun end-face distribution was obtained. An experimental platform was built, and a validation experiment was set up. Through the analysis and processing of the data of three experiments, the temperature variation curve of each diameter on the inner surface of the end-face mold was obtained. We compare and analyze the simulation and experimental results to determine the feasibility of the FDS + ANSYS method and the correctness and accuracy of the simulation model and the results.

Influence of Phonon Dispersion on Transient Thermal Response of Silicon-on-Insulator Transistors Under Self-Heating Conditions

2006 ◽  
Vol 129 (7) ◽  
pp. 790-797 ◽  
Author(s):  
Rodrigo A. Escobar ◽  
Cristina H. Amon
Keyword(s):  
Computational Models ◽  
Phonon Dispersion ◽  
Thermal Response ◽  
Domain Size ◽  
Phonon Transport ◽  
Silicon On Insulator ◽  
Nonlinear Relation ◽  
Temperature Levels ◽  
Transient Thermal ◽  
Transient Thermal Response

Lattice Boltzmann method (LBM) simulations of phonon transport are performed in one-dimensional (1D) and 2D computational models of a silicon-on-insulator transistor, in order to investigate its transient thermal response under Joule heating conditions, which cause a nonequilibrium region of high temperature known as a hotspot. Predictions from Fourier diffusion are compared to those from a gray LBM based on the Debye assumption, and from a dispersion LBM which incorporates nonlinear dispersion for all phonon branches, including explicit treatment of optical phonons without simplifying assumptions. The simulations cover the effects of hotspot size and heat pulse duration, considering a frequency-dependent heat source term. Results indicate that, for both models, a transition from a Fourier diffusion regime to a ballistic phonon transport regime occurs as the hotspot size is decreased to tens of nanometers. The transition is characterized by the appearance of boundary effects, as well as by the propagation of thermal energy in the form of multiple, superimposed phonon waves. Additionally, hotspot peak temperature levels predicted by the dispersion LBM are found to be higher than those from Fourier diffusion predictions, displaying a nonlinear relation to hotspot size, for a given, fixed, domain size.

Determination of the temperature field of a wedge during heating and cooling

1973 ◽  
Vol 24 (1) ◽  
pp. 112-115
Author(s):  
V. A. Ostaf'ev ◽  
A. A. Chernyavskaya
Keyword(s):  
Temperature Field ◽  
Heating And Cooling

Modeling and Design of Building-Integrated Thermoelectrics

2011 ◽  
Author(s):  
Leon M. Headings ◽  
Gregory N. Washington
Keyword(s):  
Thermal Response ◽  
Heat Pumps ◽  
Coefficient Of Performance ◽  
Conventional Heating ◽  
Net Energy ◽  
Arbitrary Boundary ◽  
Heating And Cooling ◽  
Temperature Oscillations ◽  
Wall Structures ◽  
And Control

The goal of this research is to develop a framework for replacing conventional heating and cooling systems with distributed, continuously and electrically controlled, building-integrated thermoelectric (BITE) heat pumps. The coefficient of performance of thermoelectric heat pumps increases as the temperature difference across them decreases and as the amplitude of temperature oscillations decreases. As a result, this research examines how thermal insulation and mass elements can be integrated with thermoelectrics as part of active multi-layer structures in order to minimize net energy consumption. In order to develop BITE systems, an explicit finite volume model was developed to model the dynamic thermal response of active multi-layer wall structures subjected to arbitrary boundary conditions (interior and exterior temperatures and interior heat loads) and control algorithms. Using this numerical model, the effects of wall construction on net system performance were examined. These simulation results provide direction for the ongoing development of BITE systems.

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