Fluid Dynamics 2

Fluid Dynamics 2

1. Continuity equation

   • changeM = PchangeinV = PAVchangeint
   • If mass flow rate 1 > 2, fluid entering faster than its leaving
     • I(M) = M/t
       • I(v) = Av
   • steady - state: AV(1) = AV(2)

2. Bernoulli Equation

   • Invisid fluid in a steady streamlined flow (comparing section)
   • Small parcel - intergrate
     • F= -AchangeinP
     • dP = -pvdv
   • (1) P+0.5v^2p = (2) P+0.5v^2p
     • Horizontal
   • P + 0.5v^2p +ghp = const
     • Non- horz

3. Venturi effect

   • As fluid passes obstruction: v increases, P drops
   • V in ratio with v

4. Torrecilli's law

   • v of water leaving(tap), of open top tank
   • v = [2g(y - y)]^0.5

5. Posseuille law

   • Reistance = (8piL/A^2)n
   • Law: I(v) = {pir^4 / 8n}{changep/L}

6. Viscosity (n)

   • Force to overcome = nAdv/dz