After sunset, radiant energy can be sensed by a person standing near a brick wall. Such walls frequently have a surface temperature around 44 degree celsius, and the typical brick emmisivity value is approximately 0.92. What would be the radiant heat flux per square meter from a brick wall at this temperature?
Consider an airplane in an accelerated climb. At a given instant in this climb, the specific excess power is 120 ft/s
Consider an airplane flying at 620 mi/h at 35,000 ft. Calculate its energy height.
For a turbojet-powered airplane with the altitude variation of thrust given by Eq. (3.19), show that as the altitude increases, the maximum velocity decreases.
The BD-5J is equipped with plain flaps. The airfoil section at the wing root is an NACA 64-212, and interestingly enough, it has a thicker section at the tip, an NACA 64-218.
For the BD-5J, calculate (a) The maximum value of CL/CD (b) The maximum value of CL^(1/ 2) /CD
A smooth, steady stream of liquid (density, rho;) emanates downward from a circular faucet (to the atmosphere). The exit area of the faucet is A1. The volumetric flow rate is Q. Find the weight of the given section of the fluid stream.
Consider a length of pipe bent into a U-shape. The inside diameter of the pipe is \(0.5\;m\). Air enters one leg of the pipe at a mean velocity of \(100\; m/s\) and exits the other leg at the same magnitude of velocity, but moving in the opposite direction. Calculate the magnitude and direction of the force exerted on the pipe by the airflow.
Consider a flow field in polar coordinates, where the stream function is given as \(ψ = ψ(r, θ)\). Starting with the concept of mass flow between two streamlines, derive Equations \(\rho V_{r}=\frac{1}{r}\frac{\partial \bar{\psi }}{\partial \theta}\) and \(\rho V_{\theta}=-\frac{\partial\bar{\psi} }{\partial r}\).
Calculate the stream function and velocity potential.Using your results, show that lines of constant \( \phi\) are perpendicular to lines of constant \(\psi\).
