To investigate the effect of airfoil shape design on aerodynamics of the airfoil, a new modified airfoil shape design is introduced in this paper. Thick symmetrical NACA 0021 airfoil is used as base model in this study that the trailing edge end curvature was altered in design shape to be inflated to have 25%, 50% and 100% scaled of the leading-edge curvature at the same cord length and same maximum thickness data. Numerical investigation, using shear-stress transport kω-SST turbulence model, is performed to study the effect of airfoil trailing edge inflation on the aerodynamic characteristics at low Reynolds Number. The base airfoil model, NACA0021, is validated numerically and shows a good agreement with previous experimental results. The results show that the new modified airfoil with 100% inflation delays the flow separation to higher angle of attack and increases the maximum lift coefficient about 40% compared with the base NACA0021 airfoil.