Heat transfer and hydraulic resistance of a flat channel with discrete wall roughness in the form of inclined trench dimples
I.A. Davletshin1, N.S. Dushin1, O.A. Dushina1, N.I. Mikheev1, R.R. Shakirov1, S.A. Isaev2
1Institute of Power Engineering and Advanced Technologies, FRC “Kazan Scientific Center RAS”, Kazan, Russia
2State Marine Technical University, Saint Petersburg, Russia
Keywords: dimples, heat-transfer intensification, hydraulic resistance
Abstract
An experimental study of heat transfer and hydraulic losses in a channel with one wall being a surface with trench dimple, was carried out. The working surface had four rows of dimples located alternately at angles of 45° and -45° to the channel axis. In the laminar regime, the transfer of heat and the losses of pressure turned out to be close to the parameters of a smooth channel. In the turbulent regime, a 1.5-fold intensification of heat transfer with respect to the transfer of heat in a smooth channel was obtained. The dependence of the increase in pressure losses on the Reynolds number qualitatively agreeing with the dependence for the channels with sandy roughness is obtained.
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