Empirical method to obtain heat transfer coefficient How to set up an experimental test? Let' s say you want to know the heat transfer rate of an airplane wing(with fuel inside) flying at steady conditions wing surface What are the parameters involved? Ⅴ Telocity, wing length. L Prandtl number, Pr -viscosity, u Nusselt number. Nu Which of these can we control easily? Looking for the relation Experience has shown the following relation works well Nu=cRe pr L r Heat Transfer Su Yongkang School of Mechanical EngineeringHeat Transfer Su Yongkang School of Mechanical Engineering # 7 Empirical method to obtain heat transfer coefficient • How to set up an experimental test? • Let’s say you want to know the heat transfer rate of an airplane wing (with fuel inside) flying at steady conditions…………. • What are the parameters involved? – Velocity, –wing length, – Prandtl number, –viscosity, – Nusselt number, • Which of these can we control easily? • Looking for the relation: Experience has shown the following relation works well: T ,U Twing surface U L Pr  Nu m n Nu = C Re L Pr