Flow Turbulence Combust DOI 10.1007/s10494-016-9716-7 DNS Analysis of Wall Heat Transfer and Combustion Regimes in a Turbulent Non-premixed Wall-jet Flame Zeinab Pouransari 1 · Luc Vervisch 2 · Laszlo Fuchs 1 · Arne V. Johansson 1 Received: 15 April 2015 / Accepted: 27 January 2016 © Springer Science+Business Media Dordrecht 2016 Abstract Understanding the heat-release effects on the wall heat transfer in turbulent react- ing flows, i.e. heat transfer with or without significant density variation, is essential for a wide variety of industrial flows, especially combustion problems. The present study focuses on the wall heat transfer and the near-wall reaction characteristics. The heat-release effects on the wall heat transfer and skin-friction coefficients are investigated using three- dimensional direct numerical simulations of a turbulent reacting wall-jet flow with and without heat release. Reductions in the skin-friction coefficient are observed in the exother- mic case, compared to the isothermal one, and the underlying mechanism is explained. The absolute wall heat flux also increases, while the corresponding Nusselt number decreases with increasing heat release. Furthermore, the wall effects on the near-wall average burning rate are assessed. It is found that the isothermal cold wall results in an appreciable decrease of the burning rate in the exothermic cases. We observed indications that the wall increases the chances for the development of the premixed mode and its occurrence is very fast in the wall-normal direction. Keywords Direct numerical simulation · Wall heat transfer · Non-Premixed combustion · Turbulent wall-jet · Skin friction coefficient · Flame index 1 Introduction The wall heat transfer and shear stress are two major important quantities of interest in industrial flows, including combustion problems. In wall-bounded combustion applications,  Zeinab Pouransari zeinab@mech.kth.se 1 Linn´ e FLOW Centre, KTH Mechanics, SE-100 44 Stockholm, Sweden 2 CORIA - CNRS and INSA de Rouen, Technopole du Madrillet, BP 8, 76801, Rouen, France