#### Aircraft Propulsion

A jet engined aircraft is required to cruise for 3000 km at a constant altitude of 8 km. At the end of cruise the aircraft will weigh 112.4 kN.The wing area of the aircraft is 80 m², CD for the flight is 0.04, CL is 0.3 and the aircraft's thrust specific fuel consumption is 10-5 kg N-1 s-¹. How much fuel will be used in the cruise? The answer should have units of kN.

The jet engines of an aircraft produce amaximum thrust, Tmax that is proportional to density:9 Tmax= The wing surface area of the aircraft is 71 m².What zero lift coefficient of drag, CDO will the aircraft have if its absolute ceiling is atan altitude of 10 km and its maximum cruisespeed is 199 m s¹ at an altitude of 8 km?

A propeller-driven aircraft has a maximum endurance of 14.1 hours when flying according to cruise climb conditions. What is the range of the flight if the aircraft's speed is 68 m s™¹, the propeller efficiency is 0.85 and the specific fuel consumption is 10-7 kg W-¹ s-¹? The answer should have units of km.

2. Briefly explain the following concepts (a) Wetted aspect ratio (b) Rubber-engine sizing (c) Mission profile (d) Thrust matching

3. Explain on the effects of the following aerodynamic/wing characteristics. You can simply summarize what is written in the textbook. (a) Airfoil thickness ratio (b) Aspect ratio (c) Wing sweep (d) Wetted aspect ratio

1. Consider the ASW design example in Chapter 3. (a) What would be the estimate of takeoff gross weight (using the method in Chapter 3) if the requirement of the cruise speed changes to: Mach 0.25, and Mach 0.85. Consider a turboprop engine for the first case. (b) What would be the estimate of takeoff gross weight (using the method in Chapter 3) if the requirement of the (one-way) cruise range speed changes to: 1000 miles and 2000miles. (c) What would be the estimate of takeoff gross weight (using the method in Chapter 3) if the requirement of the loitering period at the mission location changes to : 2 hrs and5 hrs. (d) The aspect ratio used in the textbook example was 7. What would be the takeoff gross weight, if this value changes to 5.5?