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This study investigates the heat flux of different types of phone cases (metal, leather, plastic) and their ability to dissipate heat. The results show that while metal cases are effective in heat transfer, plastic and leather cases perform similarly.
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Heat Transfer Winter 2014 Westley Christensen and Kendal Frogget Heat Flux through Smart Phone Cases
Introduction • What type of phone case has the best heat flux? • Three types of phone cases used • Metal • leather • Plastic
Problem Setup Heat Properties • Aluminum: • k=167 W/m2K • t=1mm • Leather: • k=.159 W/m2K • t=1.57mm • Plastic: • k=.2 W/m2K • t=1.5mm • For the estimated heat flux, contact resistance was assumed to be 0 and the convection coefficient to be the same for all cases. Thickness (t) Phone Case q” (Uniform heat source) T∞= 12 W/m2*K RContact Rcond Rconv
Solution and Procedure • Phone was ran using a hand warmer app until steady state temperature was reached. • The temperature of the surface was measured using a heat gun. • Heat flux was calculated based on surface temperature • Calculations shown in appendix
Conclusion • The experimental results were accurate with plastic and leather but were off with the aluminum. • The two reasons that we believed this to be the case was because the aluminum was at a colder starting temperature and dsitrubuted the heat evenly throughout the material rather than having a localized heat transfer. • Metal would still be recommended as the cover material to dissapate the generated heat but not burn your hand. Plastic and leather are about the same.
Appendix Predicted heat flux calculations: q”= (T1-T∞)/A(Rcond+Rconv), ARcond=1/k, ARconv=1/h Experimental heat flux: Gr=gβ(Ts-T∞)L3/ν2, Nu=(Gr/4)1/4 ×g(Pr), h=Nu×k/L, q”=h(Ts-T∞) L=4A/P=.2m