This project is focused on the study of a blended wing body, a concept which theoretically promises improved aerodynamic performance over existing designs. It is an unconventional configuration different from the commercial wing and tube design. The examined wing body is BW11 Eagle Ray aircraft, designed by the 2011 Group Design Project of the Aerospace Vehicle Design MSc at Cranfield University. The baseline model was designed for subsonic cruise and is now studied in transonic field and its aerodynamic parameters such as lift and drag coefficients, lift-drag ratio and span wise pressure distribution are investigated using Computational Fluid Dynamics. The aim of the study is to analyse the aerodynamic performance of BW11 concept at transonic cruise Mach Number as a preliminary stage in its redesign for transonic flight.