Evaporation Heat Transfer in Sintered Porous Media

Hanlon, M. A.; Ma, Hongbin

doi:10.2514/6.2002-3092

Cited by 3 publications

(1 citation statement)

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“…The first category is the influence of structure parameters, flow characteristics, fluid properties, physical parameters and heat-transfer characteristics on heat-and-mass transfer performance in porous substrate [30][31][32][33][34][35][36]. Hanlon et al researched the influences of the thin film evaporation, the particle size, the porosity, and the wick structure thickness on the evaporation heat transfer in sintered wick structure based on a two-dimensional heat-transfer model [37]. The heat transfer performance of a solid/liquid phase-change thermal energy storage system that includes porous metal foam was investigated by Siahpush.…”

Section: Introductionmentioning

confidence: 99%

Numerical Investigation on Heat-Transfer and Hydromechanical Performance inside Contaminant-Insensitive Sublimators under a Vacuum Environment for Spacecraft Applications

Gao

et al. 2019

Energies

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The contaminant-insensitive sublimator (CIS) is a novel water sublimator in development, which uses two porous substrates to separate the sublimation point from the pressure-control point and provide long-life effective cooling for spacecraft. Many essential studies need to be carried out in the field. To overcome the reliability issues such as ice breakthrough caused by large temperature or pressure differences, the CIS development unit model, the mathematical models of heat and mass transfer and the evaluation coefficient have been established. Numerical investigations have been implemented aiming at the impacts of physical properties of porous substrate, physical properties of working fluid, orifice layouts and orifice-structure parameters on the characteristics of flow field and temperature field. The numerical investigation shows some valuable conclusion, such as the temperature uniformity coefficient at the bottom surface of the large pore substrate is 0.997669 and the pressure uniformity coefficient at the same surface is 0.85361267. These numerical results can provide structure and data reference for the CIS design of lunar probe or spacesuit.

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Section: Introductionmentioning

confidence: 99%

Numerical Investigation on Heat-Transfer and Hydromechanical Performance inside Contaminant-Insensitive Sublimators under a Vacuum Environment for Spacecraft Applications

Gao

et al. 2019

Energies

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Development of an Experimental Small Loop Heat Pipe with Polytetrafluoroethylene Wicks

Nagano

Fukuyoshi

Ogawa

et al. 2011

Journal of Thermophysics and Heat Transfer

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This paper reports the development of an experimental small loop heat pipe with polytetrafluoroethylene (PTFE) wicks. Three kinds of PTFE porous materials were fabricated, and their wick properties were evaluated. It was clarified that the peak pore radii of the PTFE porous materials ranged from 0.8 to 2:2 m, and their porosities ranged from 27 to 50%. A small loop heat pipe with PTFE wicks was designed using these properties, and an experimental small loop heat pipe, for which the wick in an evaporator is exchangeable, was fabricated. The experimental loop was tested with 1.2 and 2:2 m PTFE wicks under atmospheric conditions. The test result with a 2:2 m PTFE wick showed a high operating temperature, possibly due to vapor leak from the evaporator grooves to the compensation chamber. The test results with the 1:2 m PTFE wick showed a lower operating temperature, lower thermal resistance, and stable operation of the loop heat pipe. Nomenclature D I Wick = inner diameter of wick, m D O Wick = outer diameter of wick, m K = permeability, m 2 k Eff = effective thermal conductivity, W m 1 K 1 k L = thermal conductivity of liquid, W m 1 K 1 k Wick = thermal conductivity of wick material, W m 1 K 1 L Wick = active length of wick, m _ m Wick = mass flow rate of fluid through wick, kg s 1 P Cap = capillary limit, Pa _ Q HL = heat leak through wick, W _ Q Load = heat load to evaporator, W R E C = thermal resistance between evaporator and condenser, K=W r Pore = pore radius of wick, m T SatCore = saturation temperature of wick core, K T SatEvap = saturation temperature of evaporator, K T Cond = average temperature of condenser, K T Evap = average temperature of evaporator, K P Cond = pressure drop of condenser, Pa P Grv = pressure drop of grooves of wick, Pa P LL = pressure drop of liquid line, Pa P Tot = total pressure drop in LHP, Pa P VL = pressure drop of vapor line, Pa P Wick = pressure drop across wick, Pa P G = gravity head, Pa " = porosity, % = contact angle, deg. L = viscosity of liquid, Pa s L = density of liquid, kg m 3 = surface tension, N m 1

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