Under the back-side windy condition,the convection and radiation heat transfer characteristics in an iso-flux upward-facing cylindrical cavity were studied by three-dimensional numerical simulation.The impacts of cavity tilt angle,wind incident angle and wind speed on convection and radiation heat transfer Nusselt number Nuc and Nur were analyzed,and the possible explanations for their impacts were presented.Results show that due to the disturbance of wind,the influence of cavity tilt angle becomes more complicated and is related to wind incident angle and wind speed.The variation of Nuc or Nur with wind incident angle is different for different cavity tilt angles.Despite of the changes of cavity tilt angle or wind incident angle,the Nuc increases with the wind speed while the Nur presents a declination with the increasing of wind speed.Hence,compared with cavity tilt angle and wind incident angle,wind speed may be the dominant factor affecting or controlling the convective and radiation heat transfer of cavity.