TY - JOUR
T1 - Development of energy efficient structured plates with zigzag arrangement of multirow inclined oval trench dimples
AU - Isaev, Sergey
AU - Leontiev, Alexandr
AU - Gritskevich, Mikhail
AU - Nikushchenko, Dmitry
AU - Guvernyuk, Sergey
AU - Sudakov, Alexandr
AU - Chung, Kung Ming
AU - Tryaskin, Nikita
AU - Zubin, Mikhail
AU - Sinyavin, Alexey
N1 - Publisher Copyright:
© 2022 Elsevier Masson SAS
PY - 2023/2
Y1 - 2023/2
N2 - A numerical study of the anomalous intensification of the turbulent heat transfer is performed for the initial hydrodynamic section of a long flat plate with a single row dense package of 16 inclined Oval Trench Dimples (OTD). Multiblock overlapping grids are used to solve Reynolds-Averaged Navier-Stokes (RANS) equations in the framework of VP2/3 in-house code. Firstly, applicability of RANS approach is confirmed by thorough comparison against the experimental measurements of the pressure distributions for a single inclined OTD mounted on a flat plate. Then, the dense package of OTD with the inclination angle of 60° is compared against Spherical Dimple (SD) at the same Reynolds number of 6000 based on the trench width and for the same trench depth and relatively high density of dimples. For OTD a progressive increase of the pressure drop is observed between the zone of deceleration of the free flow and the zone of low pressure near the inlet of spherical segments, where a tornado-like vortex is developed. Moreover, a gradual amplification of the reverse secondary flow is observed for OTD resulting in the minimum relative friction coefficient of −4 and the maximum relative Nusselt number of 4.4. Finally, acceleration and substantial thinning of the boundary layer above the upstream part of the OTD are observed. A new type of energy-efficient structured surfaces ready for additive technologies is proposed and justified for heat exchangers.
AB - A numerical study of the anomalous intensification of the turbulent heat transfer is performed for the initial hydrodynamic section of a long flat plate with a single row dense package of 16 inclined Oval Trench Dimples (OTD). Multiblock overlapping grids are used to solve Reynolds-Averaged Navier-Stokes (RANS) equations in the framework of VP2/3 in-house code. Firstly, applicability of RANS approach is confirmed by thorough comparison against the experimental measurements of the pressure distributions for a single inclined OTD mounted on a flat plate. Then, the dense package of OTD with the inclination angle of 60° is compared against Spherical Dimple (SD) at the same Reynolds number of 6000 based on the trench width and for the same trench depth and relatively high density of dimples. For OTD a progressive increase of the pressure drop is observed between the zone of deceleration of the free flow and the zone of low pressure near the inlet of spherical segments, where a tornado-like vortex is developed. Moreover, a gradual amplification of the reverse secondary flow is observed for OTD resulting in the minimum relative friction coefficient of −4 and the maximum relative Nusselt number of 4.4. Finally, acceleration and substantial thinning of the boundary layer above the upstream part of the OTD are observed. A new type of energy-efficient structured surfaces ready for additive technologies is proposed and justified for heat exchangers.
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U2 - 10.1016/j.ijthermalsci.2022.107988
DO - 10.1016/j.ijthermalsci.2022.107988
M3 - Article
AN - SCOPUS:85140898796
SN - 1290-0729
VL - 184
JO - International Journal of Thermal Sciences
JF - International Journal of Thermal Sciences
M1 - 107988
ER -