Open AccessHEAT TRANSFER IN GRADIENT TURBULENT BOUNDARY LAYER
Author(s) -
А. А. Авраменко,
М. M. Kovetskaya,
E.A. Kondratieva,
T. V. Sorokina
Publication year - 2019
Publication title -
teplofìzika ta teploenergetika
Language(s) - English
Resource type - Journals
eISSN - 2663-7235
pISSN - 2663-7243
DOI - 10.31472/ttpe.4.2019.3
Subject(s) - boundary layer , pressure gradient , turbulence , mechanics , churchill–bernstein equation , heat transfer coefficient , heat transfer , temperature gradient , thermodynamics , adverse pressure gradient , film temperature , pressure coefficient , flow (mathematics) , boundary layer thickness , flow separation , materials science , nusselt number , physics , meteorology , reynolds number
Effect of pressure gradient on heat transfer in turbulent boundary layer is constantly investigated during creation and improvement of heat exchange equipment for energy, aerospace, chemical and biological systems.
The paper deals with problem of steady flow and heat transfer in turbulent boundary layer with variable pressure in longitudinal direction. The mathematical model is presented and the analytical solution of heat transfer in the turbulent boundary layer problem at positive and negative pressure gradients is given. Dependences for temperature profiles and coefficient of heat transfer on flow parameters were obtained.
At negative longitudinal pressure gradient (flow acceleration) heat transfer coefficient can both increase and decrease. At beginning of acceleration zone, when laminarization effects are negligible, heat transfer coefficient increases. Then, as the flow laminarization increases, heat transfer coefficient decreases. This is caused by flow of turbulent energy transfers to accelerating flow.
In case of positive longitudinal pressure gradient, temperature profile gradient near wall decreases. It is because of decreasing velocity gradient before zone of possible boundary layer separation.