EML 4711/5710 Gas Dynamics 10/14/02
Closed notes Van Dommelen 3:20-4:40 pm

• The book and a calculator may be used.
• Show all reasoning and intermediate results leading to your answer, or credit will be lost.
• Where tables are used, list table and column number.
• Unless otherwise noted, the gas is air, R = 287 m²/sec² K = 1716 ft²/sec² R.
• You must use only the unit system (SI or British) used in the question to answer them. 1 BTU = 778 ft lbf, 1 slug = 32.2 lbm.
• Standard sea level conditions are p = 101,325 Pa = 2116 lbf/ft², T = 288 K = 518.4 R.

1.

A pitot probe on a plane flying at sea level measures a pitot pressure p_p of 150 10³ N/m². Find the temperature right before the tip of the tube. Assume atmospheric conditions are standard. Solution.

2.

Air blows down a converging-diverging duct from a big pressure vessel at 3 atm pressure. A shock occurs somewhere in the duct at a location that makes the total pressure behind the shock equal to ambient (1 atm). Find the static pressures immediately before and immediately behind this shock.

Solution.

3.

Air enters a constant diameter pipe with a Mach number of 0.5 and a static temperature of 288 K. Find the maximum amount of heat that can be added to each unit mass flowing through the pipe.

Solution.

4.

Air blows into a constant diameter pipe with a velocity of 228 ft/sec, at a temperature of 540 R and a pressure of 2 atm. It exits the pipe at ambient pressure (1 atm). If the length of the pipe is 60 ft and the friction coefficient is 0.005, find the exit Mach number, the total-pressure loss in the pipe and the required diameter of the pipe.

Solution.