Horizontal two-phase flow characterization for small diameter tubes with a capacitance sensor

Abstract

Two-phase flow modelling is strongly dependent on flow patterns. For the purpose of objective flow pattern identification, a capacitance sensor was developed for horizontal two-phase flow in small diameter tubes. Finite element simulations were made during design to study the effect of vapour distribution, wall thickness and electrode angle. A test rig was constructed and a series of experiments was done with horizontal air–water flow in a 9 mm tube. The sensor test results are presented in time, amplitude and frequency domain. Flow regime characterization with the capacitance measurements is clearly possible.

The influence of inclination angle on void fraction and heat transfer during condensation inside a smooth tube

“…The capacitive void fraction sensors used in the current study were developed by Ghent University (Canière et al, 2010(Canière et al, , 2009(Canière et al, , 2008(Canière et al, , 2007) and a calibration procedure was developed for adiabatic horizontal flow (De Kerpel et al, 2014. For the current study the sensor responses were calibrated to track the predictions of the Rouhani and Axelsson (1970) correlation for the case of horizontal adiabatic flow at a saturation temperature of 40 ᵒC; good correlation between horizontal adiabatic flow and the Rouhani and Axelsson (1970) predictions has been observed in previous work (De Kerpel et al, 2013).…”

“…The experimental system (Figure 1) was inherited from past research work in which detailed descriptions and explanations have been provided (Adelaja et al, 2014a(Adelaja et al, , 2014bCanière et al, 2007;Lips and Meyer, 2012a, 2012b, 2012cMeyer et al, 2014;Suliman et al, 2009;Van Rooyen et al, 2010). Therefore, only a brief overview will be provided in this section.…”

“…The sampling frequency of the void fraction measurements was sufficient as most two-phase flow phenomena occur at a frequency of 100 Hz (Canière et al, 2007). The Nyquist criterion for sampling was thus satisfied and aliasing of the observed void fraction signals was therefore not a challenge.…”

“…As the void fractions and heat transfer correlations are so strongly related there is a need for accurate void fraction measurements, however, instrumentation that can measure void fractions without influencing the flow patterns are not readily available commercially. Such a void fraction sensor has been developed at the Ghent University (Canière et al, 2010(Canière et al, , 2009(Canière et al, , 2008(Canière et al, , 2007, but is not yet commercially available on the open market.…”

Heat Transfer, Fluid Mechanics and Thermodynamics—HEFAT2011

“…In industry, heat transfer, fluid mechanics and thermodynamics are used in environmental studies as engineering sciences to enhance our basic understanding and design capabilities [1] of a broad range of phenomena [2][3][4][5][6][7][8][9][10], equipment [11][12][13], applications [14][15] and systems [16][17] ranging from biological systems [18][19] to common household appliances [20][21], aerospace [22][23], residential and commercial buildings [24][25], mining [26][27], industrial processes [28][29], and electronic devices [30][31]. These disciplines can also be used to conduct techno-economic analyses [32][33][34][35][36][37][38][39] for comparing different types of equipment and systems to allow decisions in terms of capital and running costs in comparison with the cost of financing and impact on the environment [40][41].…”