Infrared thermography of a pulsating heat pipe: Flow regimes and multiple steady states

Time-strip visualization and thermo-hydrodynamics in a Closed Loop Pulsating Heat Pipe

“…The latter depends not only on the boundary conditions (geometry, temperature levels, and filling ratios) but also on the two-phase flow pattern present. Heat input has been observed to be the primary parameter defining the qualitative flow pattern [4], and the following general trends were observed in multi-turn [4,5] and in single-turn [6] condition is the one producing the best heat transfer performance, as confirmed by the local evaporator heat transfer measurements carried out by Mameli et al [7] and by infra-red evaporator temperature measurements of Karthikeyan et al [8].…”

“…In this context, obtaining qualitative visual images of the different flow regimes and quantitative information regarding their dynamics would help to clarify the physics involved, especially with regards to their relative thermal behavior. Since a systematic spatio-temporal analysis of the flow behavior, including the coupling between the two-phase flow motion and the resulting temperature oscillations is still lacking in the literature [3,8], the objective of this work is to present the results attained through synchronized thermal and visual investigation of a single closed loop pulsating heat pipe (CLPHP). The time-strip image processing technique implemented by Borhani et al [17] has been utilized to obtain a 2D space-time representation of the flow inside the PHP channels, which can be further processed to extract accurate qualitative and quantitative information.…”

Pulsating Heat Pipe Simulations: Impact of PHP Orientation

“…3 PHP stable operation at different orientations Karthikeyan et al (2014) described the regimes of stable operation which are observed experimentally in the PHP: continuous oscillations, intermittent or stopover regime and dryout. Our simulations also produce these regimes.…”

A mass-spring-damper model of a pulsating heat pipe with a non-uniform and asymmetric filling

“…When the liquid moves from the evaporator to condenser section, heat can be transferred 385 by convection which is much more efficient than by conduction only. Therefore, the thermal resistance decreases with increase in heat input.These observations also indicate that when the fluid is in a translational or in a combined motion, [16].…”