Civil Engineering Questions
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Ali Hamza
Ali Hamza
26 Jan 2019

What are Real and Ideal Fluids??


When a real fluid flows past a boundary, the fluid immediately in contact with the boundarywill have the same velocity as the boundary. The velocity of successive layers of fluid willincrease as we move away from the boundary.The part of the flow adjoining the boundary in whichthis change of velocity occurs is known as theboundary layer. In this region, shear stresses aredeveloped between layers of fluid moving withdifferent velocities as a result of viscosity and theinterchange of momentum due to turbulence causingparticles of fluid to move from one layer to another.Outside this boundary layer, in a real fluid, the effectof the shear stresses due to the boundary can beignored and the fluid can be treated as if it were anideal fluid, which is assumed to have no viscosityand in which there are no shear stresses, whichgreatly simplifies the analysis of the flow and stillleads to useful results.