Open Access

ARTICLE

Expression for the Gradient of the First Normal Derivative of the Velocity Potential

Zai You Yan¹

1 Department of Aerodynamics, Nanjing University of Aeronautics and Astronautics, Yu Dao Street 29, City of Nan Jing, Jiang Su Province, P. R.China, 210016. Email: jutsjtu@yahoo.com.cn