Analysis Model and Numerical Simulation of Thermoelectric Response of CFRP Composites
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Analysis Model and Numerical Simulation of Thermoelectric Response of CFRP Composites Yueguo Lin 1
Received: 24 April 2018 / Accepted: 29 April 2018 # Springer Science+Business Media B.V., part of Springer Nature 2018
Abstract An electric current generates Joule heating, and under steady state conditions, a sample exhibits a balance between the strength dissipated by the Joule effect and the heat exchange with the environment by radiation and convection. In the present paper, theoretical model, numerical FEM and experimental methods have been used to analyze the radiation and free convection properties in CFRP composite samples heated by an electric current. The materials employed in these samples have applications in many aeronautic devices. This study addresses two types of composite materials, UD [0]8 and QI [45/90/−45/0]S, which were prepared for thermoelectric experiments. A DC electric current (ranging from 1A to 8A) was injected through the specimen ends to find the coupling effect between the electric current and temperature. An FE model and simplified thermoelectric analysis model are presented in detail to represent the thermoelectric data. These are compared with the experimental results. All of the test equipments used to obtain the experimental data and the numerical simulations are characterized, and we find that the numerical simulations correspond well with the experiments. The temperature of the surface of the specimen is almost proportional to the electric current. The simplified analysis model was used to calculate the balance time of the temperature, which is consistent throughout all of the experimental investigations. Keywords CFRP . Thermoelectric . Temperature . Law joule . Aeronautical Nomenclature cp Specific heat capacity (J/kg.K) g Gravity acceleration (g=9.81 m/s2) Gr Average Grashof number Grx Local Grashof number at height x
Support foundation Research project of CAUC (2016SYCX04, MHRD20160105)
* Yueguo Lin [email protected]
1
Department of Designs and Manufactures of Aircrafts, Civil Aviation University of China, CAUC 2898, Road Jinbei, District Dongli, Tianjin 300300, China
Appl Compos Mater
hx I k Nu Nux Pr Prx Ra Rax R S q q' q" t T U u0 x y
Local heat transfer coefficient (W / m2.K) Electric current intensity (A) Thermal conductivity (W/m.K) Average Nusselt number Local Nusselt number at position x Average Prandtl number Local Prandtl number at position x Average Rayleigh number Local Rayleigh number at position x Electric resistance (Ω) Area of plate (m2) Heat flow rate (W) Heat flow rate per unit length (W/m) Heat flux (W/m2) Time (s) Temperature (K) Electric voltage (V) Velocity of air (m/s) Coordinate from the base of the plate (m) Coordinate normal to the plate(m)
Greek Symbols α Fluid thermal diffusivity(m2/s) β Fluid thermal expansion rate(1/K) δ Thickness of air film (m) ε Surface emissivity μ Dynamic viscosity (kg/m.s) ρ Density (kg/m3) σE Electrical conductivity(S/m) σ Stefan-Boltzmann constant 5.67 × 10–8 W/m2.K4 λ Thermal conductivity (W/m.K) Subscripts e
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