TY - JOUR

T1 - Contact method for simultaneous measuring the liquid film thickness and temperature

AU - Gatapova, Elizaveta Ya

AU - Filipenko, Maxim A.

AU - Aniskin, Vladimir M.

AU - Kabov, Oleg A.

PY - 2018/1/1

Y1 - 2018/1/1

N2 - We present a contact method for local measurements of liquid film thickness and temperature. The sensing element is a microthermocouple with flat bead working on the Seebeck effect. The bead size of the manufactured thermocouple is less than 3 _m. A special software is developed which synchronizes microthermocouple readings and the motorized stage position, allowing automatic determination of the thickness of the liquid layer. The interface position is determined as a position of abrupt change in temperature. In some cases this measured temperature difference corresponds to the temperature jump value. In the case of the absence of a temperature difference, the interface position is determined from the difference in temperature gradients, from the so-called fracture of the temperature profile at the interface that occurs due to the difference in thermal conductivity between the gas and the liquid. Four different types of liquid, H2O, C2H5OH, CH2I2, and HFE-7100, are used in the experiments. This technique simultaneously provides data on the local film thickness and temperature profile, including the temperature value at the liquid-gas interface, using one instrument. Our measurements are in excellent agreement with the measurements by the shadow method. The method can be adopted for measurements of void fraction in two-phase flow. In the case of the existence of measurable temperature jump the thermal resistance of the liquid-gas interface can be estimated.

AB - We present a contact method for local measurements of liquid film thickness and temperature. The sensing element is a microthermocouple with flat bead working on the Seebeck effect. The bead size of the manufactured thermocouple is less than 3 _m. A special software is developed which synchronizes microthermocouple readings and the motorized stage position, allowing automatic determination of the thickness of the liquid layer. The interface position is determined as a position of abrupt change in temperature. In some cases this measured temperature difference corresponds to the temperature jump value. In the case of the absence of a temperature difference, the interface position is determined from the difference in temperature gradients, from the so-called fracture of the temperature profile at the interface that occurs due to the difference in thermal conductivity between the gas and the liquid. Four different types of liquid, H2O, C2H5OH, CH2I2, and HFE-7100, are used in the experiments. This technique simultaneously provides data on the local film thickness and temperature profile, including the temperature value at the liquid-gas interface, using one instrument. Our measurements are in excellent agreement with the measurements by the shadow method. The method can be adopted for measurements of void fraction in two-phase flow. In the case of the existence of measurable temperature jump the thermal resistance of the liquid-gas interface can be estimated.

KW - Evaporation

KW - Liquid film thickness

KW - Liquid-gas interface

KW - Microthermocouple

KW - Temperature jump

KW - Temperature measurements

KW - Thermal resistance

KW - Void fraction

KW - microthermocouple

KW - temperature measurements

KW - void fraction

KW - FLOW

KW - thermal resistance

KW - INTERFACE

KW - liquid film thickness

KW - temperature jump

KW - liquid-gas interface

KW - evaporation

KW - WATER

UR - http://www.scopus.com/inward/record.url?scp=85068687143&partnerID=8YFLogxK

U2 - 10.1615/InterfacPhenomHeatTransfer.2018029685

DO - 10.1615/InterfacPhenomHeatTransfer.2018029685

M3 - Article

AN - SCOPUS:85068687143

VL - 6

SP - 187

EP - 196

JO - Interfacial Phenomena and Heat Transfer

JF - Interfacial Phenomena and Heat Transfer

SN - 2169-2785

IS - 3

ER -