d) A two bladed propeller of 2.5 m diameter and blades with uniform chord length 20 cm operates at rotational speed 1800 rpm and flight speed 60 ms- at which the inflow factor is 0.05. The blade aerofoil section has lift curve slope 27 per radian and drag coefficient 0.09. For the propeller design the angle of attack is to be 4 degrees along each blade. (i) Evaluate the advance angle at radial position 0.8 m along the blade, and what is the blade pitch angle at this position, (ii) Find the blade pitch at the propeller tip, (iii) What is the degree of twist between the above two spanwise locations? [10] e) Table 1 shows the distribution of the thrust coefficient gradient for calculation of propeller thrust using blade element theory. Calculate the thrust coefficient from the data. [10] Table 1: Blade element information for question 1 dCT da 0.3 0.0305 0.4 0.0464 0.5 0.0733 0.6 0.1005 0.7 0.1328 0.8 0.1818 0.9 0.2081 1 0.2709