Fluid-Mechanics-Group-Assignment-Lukes-Part

Having trouble with solving this engineering problem.

Assume that, at a point on the wing of the concorde supersonic transport, the air temperature is -19.3c and the pressure is 1.75x10^4 N/m 2. Calculate the density (in kg/m^3) at this point. Note: Specific Heat of Air in Metric Unit, R = 287j/kg*K

Long flights at midlatitudes in the Northern Hemisphere encounter the jet stream, an eastward airflow that can affect a plane's speed relative to Earth's surface. If a pilot maintains a certain speed relative to the air (the plane's airspeed), the speed relative to the surface (the plane's ground speed) is more when the flight is in the direction of the jet stream and less when the flight is opposite the jet stream. Suppose a round-trip flight is scheduled between two cities separated by 3200 km, with the outgoing flight in the direction of the jet stream and the return flight opposite it. The airline computer advises an airspeed of 810 km/h, for which the difference in flight times for the outgoing and return flights is 72 min. What jet-stream speed is the computer using?

A one-third scale model of an airplane is to be tested in water. The airplane has a velocity of 900 km/h in air at −50°C. The water temperature in the test section is 10°C.                                                                                                 The properties of air at 1 atm and −50°C: ? = 1.582 kg/m3, ? = 1.474 × 10−5 kg/m·s.                                                                                The properties of water at 1 atm and 10°C: ? = 999.7 kg/m3, ? = 1.307 × 10−3 kg/m·s.                                                                                                  In order to achieve similarity between the model and the prototype, the water velocity on the model should be (a) 97 km/h (b) 186 km/h (c) 263 km/h (d ) 379 km/h (e) 450 km/h

A spaceship has crashed into an ocean on an unknown planet with radius 6.42 * 10 ^ 6 * m and mass 5.82 * 10 ^ 24 The atmospheric pressure at sea level is 202.0 kPa and the ocean has density of 0.817 * 10^ 3 kg/m3 . If the spacecraft can withstand external pressure of 3 atm how deep will the craft sink before being crushed?

1. Suppose you are flying a 7,784 kilograms aircraft at 14,630 meters where the air density is 0.2062 kilograms/cubic meter. Your current cruising speed is 290 kilometers/hour (108 m/s) and the wing area of the aircraft is 186 square meters. You need to make some altitude changes and will need to know the "Lift Coefficient" of the aircraft in order to do so. What is theCl for your aircraft?

2. The speed v of an object being propelled through water is given by (2P v(P,C) = kC where P is the power being used to propel the object, C is the drag coefficient, and k is a positive constant. Swimmers can therefore increase their swimming speeds by increasing their power or reducing their drag coefficients. To compare the effect of increasing power versus reducing drag, we need to somehow compare the two in common units. A frequently used approach is to determine the percentage change in speed that results from a given percentage change in power and in drag. If we work with percentages as fractions, then when power is changed by a fraction r (with r corresponding to 100x percent), P changes from P to P+xP. Likewise, if the drag coefficient is changed by a fraction y, then C changes from C to C + yC. Then, the corresponding fractional change in speed is v(P+xP,C+yC) – v(P,C) v(P,C') 1 which then reduces to the function 1+x f(r, y) = - 1.

Q2/ Answer the following: 1) Separation in flow past a solid object is caused by (a) a favourable (negative ) pressure gradient (b) an adverse ( positive ) pressure gradient (c) the boundary layer thickness reducing to zero 2) In the design, we have to delay the separation point in order to reduce wake size (T/F) 3) Define Mach number, boundary layer and shock wave. 4) when the flow is accelerates if the cross sectional area is increases (a) M 1 (c) M =1

3. Suppose the drag force on a truck is given by the equation: F = cqu² + c2v where c = 4.80 N and c, = 111.8 N. Check that this relationship is plausible. Do the units work out? (a) Calculate the required propulsive power at a speed of 55 mi/hr. Express your final answer in Hp. Recall that 1Hp= 745.7 W. (b) Calculate the required propulsive power at a speed of 80 mi/hr. (c) Is the ratio of required powers proportional to the ratio of given speeds? Surprised? Or not?

As measured by NASA's Viking landers, the atmosphere of Mars, where g = 3.71 m/s2, is almost entirely carbon dioxide, and the surface pressure averages 700 Pa. The temperature is cold and drops off exponentially: T≈ TO e-Cz, where C 1.3 \times 10-5 m-1 and TO≈ 250 K. For example, at 20, 000 m altitude, T≈ 193 K. (a) Find an analytic formula for the variation of pressure with altitude. (b) Find the altitude where pressure on Mars has dropped to 1 Pascal.

On October 3, 1967, pilot William J. "Pete" Knight set a world record that still stands to this day for the fastest flight by a crewed, powered aircraft by flying the North American Aviation X-15 as fast as Mach 6.7 at an altitude of 102,000 ft above sea level. Mach number is the ratio of an object’s velocity to the local speed of sound. Using the table for atmospheric properties with respect to altitude, calculate the speed of sound at an altitude of 100,000 ft. What must have been the velocity of the X-15?

From Table A.3, the density of glycerin at standard conditionsis about 1260 kg/m3 . At a very high pressure of 8000 lb/in2 , itsdensity increases to approximately 1275 kg/m3 . Use this datato estimate the speed of sound of glycerin, in ft/s.

Determine the sonic velocity in air at sea level and at 10 000, 20 000, and 30 000 ft. Assume standard atmosphere. Answers :340.2m/s 328.3 m/s 315.9 m/s 303.1m/s