1. Fluid Mechanics Ch-8 Buoyancy Pressure Flow

2. Fluids Fluids flow and alter shape Which states of matter are fluid? Liquid Gas Plasma

3. Gasses fill and conform to their container Chlorine gas Cl 2

4. Plasma’s conform to magnetic fields At PPPL they are experimenting on the fusion of hydrogen plasma

5. Density  = m/V “rho” = mass/volume Density of Steam = 0.598 kg/m 3 Density of Mercury = 13.6 x 10 3 kg/m 3

6. Buoyancy F B = F g (of displaced fluid) = m o g

7. Archimedes Principle F net = m f g - m o g

8. Ships are rated as displacing tons of seawater

9. Fluid Pressure P = F/A Force/unit area Pounds/in 2 (Psi) Or N/m 2 (Pascals) 4000 N/m 2

10. 10 7 Pascal

11. Fluid Pressure P = F/A Force/unit area PSI (lbs/insquared)

12. Pressure increases as area applied decreases F 1 /A 1 = F 2 /A 2

13. Hydraulics at the Dentist

14. Syringe hydraulic lift I raise a 10 N rock with a hydraulic piston that is 13 mm in radius using water connected to a 1.5 mm radius syringe. How much force is necessary for this lift to raise the rock?

15. Pressure as a Function of Depth P = P o +  gh

16. Submarine Ballast Tanks The density of the whole device is adjusted by releasing compressed air

17. WWIII Submarine section

19. Buoyant force results from differing pressure at depth F B =A(P o +  gh 2 )-A(P o +  gh 1 ) F B =  g(h 2 -h 1 )A F B =  gV F B =m f g That’s Archimedes Principle

20. The Coanda Effect Fluid adheres to surfaces Flowing fluids are directed by curved surfaces

21. Bernouli’s Principle on Air foils Air flowing across and air foil flows faster across the top Pressure is lower of the air flows faster Fnet is upward

22. Coanda Effect breaks down at high angles of attack The Coanda effect guides the air flow along the surface The air flow breaks free and turbulent flow results Stall occurs

23. Coanda Develops First Jet engine aircraft, 1910 It crashes, he loses funding Lost technology for 30 years