scholarly journals Taylor-Couette-Poiseuille flow heat transfer in a high Taylor number test rig

2021 ◽  
Vol 5 ◽  
pp. 126-147
Author(s):  
Phillip Swann ◽  
Hugh Russell ◽  
Ingo Jahn

As technology advances, rotating machinery are operating at higher rotational speeds and increased pressures with greater heat concentration (i.e. smaller and hotter). This combination of factors increases structural stresses, while increasing the risk of exceeding temperature limits of components. To reduce stresses and protect components, it is necessary to have accurately designed thermal management systems with well-understood heat transfer characteristics. Currently, available heat transfer correlations operating within high Taylor number (above 1×10^10) flow regimes are lacking. In this work, the design of a high Taylor number flow experimental test rig is presented. A non-invasive methodology, used to capture the instantaneous heat flux of the rotating body, is also presented. Capability of the test rig, in conjunction with the use of high-density fluids, increases the maximum Taylor number beyond that of previous works. Data of two experiments are presented. The first, using air, with an operating Taylor number of 8.8± 0.8 ×10^7 and an effective Reynolds number of 4.2± 0.5 ×10^3, corresponds to a measured heat transfer coefficient of 1.67 ± 0.9 ×10^2 W/m2K and Nusselt number of 5.4± 1.5×10^1. The second, using supercritical carbon dioxide, demonstrates Taylor numbers achievable within the test rig of 1.32±0.8×10^12. A new correlation using air, with operating Taylor numbers between 7.4×10^6 and 8.9×10^8 is provided, comparing favourably with existing correlations within this operating range. A unique and systematic approach for evaluating the uncertainties is also presented, using the Monte-Carlo method.

2005 ◽  
Author(s):  
Yun Wook Hwang ◽  
Min Soo Kim

The characteristics of the evaporative heat transfer in microtubes were investigated with three circular tubes with inner diameters of 244, 430, and 792 μm, respectively. The interrelation between the heat flux and the mass flux about the heat transfer coefficients was expressed by the boiling number, which was considered to be a very important parameter to predict the trend of the heat transfer coefficients in microtubes versus the quality. A new correlation for the evaporative heat transfer coefficients in microtubes was developed by considering the following factors; the laminar flow heat transfer coefficient of liquid-phase flow, the enhancement factor of the convective heat transfer, and the nucleate boiling correction factor. The correlation developed in this study predicts the experimental heat transfer coefficients within an absolute average deviation of 8.4%.


1993 ◽  
Vol 1 (1) ◽  
pp. 115-126 ◽  
Author(s):  
George S. Dulikravich ◽  
Vineet Ahuja ◽  
Seungsoo Lee

Author(s):  
Ianto Martins ◽  
Arthur Pandolfo da Veiga ◽  
Eduardo Alves ◽  
Jader Barbosa

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