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Numerical thermal‐hydraulic performance investigations in turbulent curved channel flow with horseshoe baffles
Author(s) -
ALJuhaishi Lafta F. M.,
Mohd Ali Mas F.,
Mohammad Hafidh H.,
Ajeel Raheem K.
Publication year - 2020
Publication title -
heat transfer
Language(s) - English
Resource type - Journals
eISSN - 2688-4542
pISSN - 2688-4534
DOI - 10.1002/htj.21810
Subject(s) - baffle , nusselt number , mechanics , turbulence , heat transfer , turbulence kinetic energy , materials science , heat transfer enhancement , hydraulic diameter , thermodynamics , geometry , heat transfer coefficient , physics , reynolds number , mathematics
Abstract A numerical work is performed to investigate the thermal‐hydraulic performance in a curved channel of a journal bearing equipped with oblique horseshoe baffles. Water, a working fluid, is passed through the curved channel at a constant temperature condition of 358 K. The effects of different parameters of baffles, that is, attack angle ( α = 45°, 60°, and 90°) and the number of baffles (NB = 9 and 13 baffles), are examined. Influences of design parameters on heat transfer and friction performances are studied and displayed in terms of the Nusselt number, the friction factor, the Nusselt number enhancement ratio, and the thermal‐hydraulic performance factor (THPF). The numerical simulations present the flow structures of the tested channel in terms of velocity, isotherms, turbulent kinetic energy, and vorticity contours. The numerical results reveal that the adopted geometry of the curved channel with baffles yields a significant enhancement of heat transfer rate over the plain channel (without baffles), which is approximately 2.5 to 3.8 times. Also, the results show that the best condition to achieve maximum heat transfer is at angle α = 90°, NB = 13, and Re = 5000, compared with other conditions. Furthermore, the maximum THPF of the curved channel using baffles is 4.4 at the same condition. The results confirmed that the geometry of the baffles inside the curved channel has a remarkable impact on heat transfer improvement, accompanied by a reasonable increase in friction losses.