ENG5278:ADVANCED AERODYNAMICS 5

Q1)

(a) Name the six fundamental types of experimental analysis. [3]

(b) Name one experimental technique for species concentration measurements which uses fluorescent dyes and one which does not. [2]

(c) What are the differences between PTV and LSV? [5]

(d) Name the various components necessary to setup a Mach-Zehnder interferometer, and draw the path that a light beam takes in this setup. [4]

(e) Name five measurement techniques used for gas concentration analysis. [5]

(f) How does a porous PSP increase the response time of the paint? [4]

(g) What are the merits of dynamic PSP calibration? [2]

(h) Name the two radiative processes that are referred to as luminescence. What is their main difference? [2]

Q2)

(a) Draw an x-t diagram for a closed-ended double diaphragm shock tube and label the following key features: [10]

(i) First incident shock wave.

(ii) First contact surface.

(iii) First expansion head.

(iv) Second incident shock wave.

(v) Second contact surface.

(vi) Second expansion tail.

(vii) Reflected shock wave.

(viii) Useful run time.

(b) What are the differences between finite and acoustic waves? [5]

(c) Using the acoustic approximation, describe the process in which a shock wave is formed inside a shock tube. [6]

(d) A normal shock wave moves at a constant velocity of 500 m/s into still air (100 kPa and 0 °C). Determine the static and stagnation pressures and temperatures in the air after passage of the wave, as well as the gas velocity behind the wave. [11]

Q3)

(a) Show how simple cross-flow theory gives the normal force coefficient (based on the wing planform area) of a slender delta wing of aspect ratio, AR, to be: [15]

(b) What adverse aerodynamic force/moment components can be generated when vortex bursting occurs above a delta wing? [2]

(c) Sketch the variation of the angle of onset, αONSET, for the occurrence of vortex bursting at the trailing edge of a delta wing against its leading edge sweep angle, λ. [3]

Q4)

An aircraft’s wing planform is given by the expression below, where s is the semi-span at distance x behind the wing’s apex, and c is the wing root chord equal to 27.7m. The wing area is 385.5m2 , The landing mass is 100,000kg at a landing speed of 90m/s. Take air density to be 1.2kg/m3 .

(a) Find an expression for the total normal force on the wing planform as a function of incidence angle, α.[13]

(b) Estimate the incidence at landing. [8]