# Search results

1. ### Probability Density Functions in Fluid Mechanics

Hi all, For an exam I'm required to be able to plot the PDF of a fluctuating velocity function, say u(t)=sint(wt), using what they call the "graphical technique", but handily I can't find it anywhere in the lecture notes, and I'm struggling to find anything with a standard Google search...
2. ### Friction Velocity from Law of the Wall

Hi all, Am currently studying a set of data from a Hot Wire Anemeotry lab that was done a few days ago. The experiment was investigating a turbulent flow of air in a wind tunnel near a flat wall. As part of the write up, we're ment to find the friction velocity from the laminar near wall...
3. ### Fluid Dynamics - Spanwise Vorticity of Turbulent Boundary Layer

Hi all, Am reading a few papers for a Uni case study about structures in Turbulent Boundary Layers over a Flat Plate (water), particularly low-speed streaks. I'm confused over what mechanism causes the span wise variations in velocity that seems to cause low speed streaks. Would...
4. ### First Order Control System

Hi all, got a Control question here, and I'm struggling with what I assume is a simple algebraic step. Thanks in advance! 1. Homework Statement A closed loop control system governs the level of water in a tank (H(s)) to meet a target height (Hi(S)). The flow of water into the tank is...
5. ### Electromagnetic Induction in the Earths Field

Hi all, brand new to these forums but help you can give me some guidance with some summer exam revision! Heres a fairly simple one I can't see through for some reason, using EMF = B.u.l etc: 1. A copper disc, 250mm in diameter, is reotated at 300 rpm about a horizontal axis through its centre...