Fluid Mechanics & Dynamics

• Fluid – a material that deforms continuously and permanently under the application of a shearing stress
• Important properties

Density (ρ) Specific weight (γ) Specific Gravity (SG) Viscosity (μ)

• Streamline
  • Lines tangent to the velocity vector throughout the flow field

• Stagnation Point
  • Largest pressure obtainable along a streamline
  • Velocity is zero

• Air as a fluid
  • When studying aerodynamics air is treated as a fluid
  • Follows all laws of motion and all laws of fluid mechanics
    • • • SF = mâ
        • Conservation of Energy
        • Conservation of Mass

• Continuity equatio

Mass is conserved V1A1=V2A2

• Bernoulli equation
  • P1+1/2 ρV12 +γz1 = P2+1/2 ρV22 +γz2
  • Relationship between Pressure, Velocity, and Elevation
  • Based on conservation of linear momentum (Kinetic Energy)