• Laminar flows are characterized by a very high degree of orderliness.

Figure 1.1

• The diffusive transport processes that occurs in laminar flows are only caused by molecular motion.
  
• Laminar flow solutions can generally be obtained by integration of the set of differential equations given below:
  

  Continuity equations ( ρ = const.):

Momentum equation: j = 1, 2, 3      

• Equations for 4 unknowns U₁ , U₂ , U₃ and P are available.
  

Equations to describe damping of disturbances

Let us accept the solution as

or,

• Stable laminar flows posses a high degree of stability against outside disturbances.
  
• Short wave disturbances are better damped than long wave disturbances.
  
• If a whole spectrum of disturbances acts on a flow, the long wave disturbances are maintained longer.
  
• If externally introduced disturbances are not damped, the flow will not maintain laminar character.