Computer modeling of the vapour vortex orientation changes in the short low- temperature heat pipes

The Solving of the Inverse Thermal Conductivity Problem for Study the Short Linear Heat Pipes

“…Experimental values in the stationary state of the thermal resistance R HP of a short HP's are defined as the thermophysical characteristic of the heat transfer device as a whole [28], at a constant value of the temperature load (pressure) on the evaporator δt = T ev -T B and calculated using formula (18) and a vacuum adiabatic calorimeter, Figure 2, in which all parameters of the working HP, including temperature and transmitted thermal power, are measured using thermocouples.…”

“…Earlier calculations of the flow velocity and vapour density of diethyl ether using the Navier Stokes equation system in a short HP's vapour channel similar to the Laval nozzle [16] [18], allow us to calculate the temperature distribution in this channel. The ratio between the pressure, density and temperature of the condensing vapor in the first approximation can be given by the equation of state of an ideal gas in the following form [19] [20] [21]:…”

“…[17] [18], give interesting results. Increased film thickness (and HP's high thermal resistance) at low temperature load and a sharp de-crease in film thickness (and significantly reduced HP's thermal resistance) with increasing temperature load can be associated with a toroidal vapour vortex ro-DOI: 10.4236/eng.2022.146018 194 Engineering tation direction change [20] [21].…”

“…HP's diagram: 1: top cover; 2: cylinder body of the HP's; 3:locking element; 4: multilayer mesh capillary-porous insert with uniform dense radial cross-linking; 5: bottom cover; 6: capillary injector channels with a diameter of 1 mm; 7: bottom flat multilayer mesh evaporator. There are capacitance sensors 8, 9, 10 installed inside the top cover[16] [17][18], two of which are intended for a condensate film thickness measurement, while the third with a welded on its electrodes microthermistor CT3-19 to measure the film temperature.…”

Experimental study of linear heat pipes thermal characteristics under the external vibrations effect

“…Среднюю температуру кипящего слоя эфираТ fev на поверхности нижней крышки ТТ оценивают с помощью уравнения (2), и температура Т fev определяет частоту образования пузырьков и интенсивность парообразования в целом [30]. По мере уменьшения толщины кипящего слоя диэтилового эфира δ film коэффициент теплоотдачи α ev испарителя TT возрастает, частота и интен сивность возникновения пузырьков также возрастают до тех пор, пока толщина слоя δ film не достигнет граничной величины δ film ~ 2r min ~ 10 -5 м, равной диаметру пузырька с минимальным критическим размером.…”