Solutions to Homework Set 1: Atmospheric Pressure and Altitude Calculations - Prof. E. Cli, Assignments of Aerospace Engineering

Download Solutions to Homework Set 1: Atmospheric Pressure and Altitude Calculations - Prof. E. Cli and more Assignments Aerospace Engineering in PDF only on Docsity! HW Set 1 Solutions 25 January 2000 1) One side of the manometer is attached to the test chamber while the other is vented to the atmosphere. The pressure difference, the gauge pressure in the chamber, is manifested in the height differential in the Mervury manometer. Pc = Pa + ρgo∆h where Pc is the (absolute) pressure in the chamber and Pa is the atmospheric pressure. The pressure difference is Pc − Pa = ρgo∆h = 13, 000Kg/m3 9.807m/s2 0.75m = 95, 618N/m2. The total force is the pressure difference times the area F = (Pc − Pa) πD2/4 = 18, 775N 1 2) The mathematical models for atmospheric properties in the troposphere (0−11 km) and the lower part of the stratosphere (11−20 km) were described in class and in various notes. A MATLAB routine to implement these is available in atmosphere.mNote that this routine is written to correctly handle vector input, that is, the altitude H , can be an array and the routine returns corresponding arrays for pressure, temperature and density. The command to generate a table and a plot are % % Script file for problem 2 on H.W. Set 1 % H = [0:1000:20000]; [delta, theta, sigma] = atmosphere(H,0); A = [H’, delta’, theta’, sigma’]; save table A -ascii % H = [0:100:20000]; % finer grid [delta, theta, sigma] = atmosphere(H,0); plot(delta,H,’b’); hold; plot(theta,H,’r’); plot(sigma,H,’g’); ylabel(‘Altitude (m)’) legend(‘delta’,’theta’,’sigma’) title(‘ISA Standard Atmosphere’) . 2