The 6th International Conference on Experimental and Numerical Flow and Heat Transfer (ENFHT'21) aims to become the leading annual conference in fields related to experimental and numerical flow and heat transfer. The goal of ENFHT'21 is to gather scholars from all over the world to present advances in the relevant fields and to foster an environment conducive to exchanging ideas and information. This conference will also provide an ideal environment to develop new collaborations and meet experts on the fundamentals, applications, and products of the mentioned fields.