Estimation of the local instantaneous heat flux inside a pulsating heat pipe for space applications

Abstract Pulsating Heat Pipes (PHP) are promising and effective passive two-phase heat transfer devices in terms of high capability, efficient thermal control, adaptability low cost therefore they have been extensively studied the last years. Many authors estimated fluxes at evaporator condenser area only average values based on first principle considerations. In present study application an inverse analysis technique to experimental infrared temperature data is proposed investigate local convective flux for forced convection flow inside these along adiabatic zone. A PHP specifically designed be hosted board host International Space Station was tested microgravity during 67th Parabolic Flight Campaign organized by European Agency. The device consists aluminium tube closed a loop with 14 turns section, 3 mm inner diameter, half filled FC-72 fluid. external temperatures measured zone high-speed camera (50 Hz, 1280x1024 pixels). images thereafter post-processed adopted as input solution conduction problem pipe wall (Tikhonov regularisation method) extrapolate time-varying internal surface contact