Flurial hydraulics and basic fluid mechanics

Flurial hydraulics -: The study of flow of the water in mobile boundary channels is dealt in flurial hyraulics. The channel may be classified as mobile boundary or rigid boundary channels . Mobile boundary channels include rivers and unlined alluvial chanls , the boundaries of which are made of loose soil which can be esaly eroded and transported by flowing water .

Pressure gradient -: The pressure gradient in a fluid is equal to the body force per unit volume and acts in the same direction.      The term pressure gradient ( grad p ) = ρ K = ρ ( ix + jy + kz ) , where i,j and k are the unit vectors in the direction of the axes of the coordinate system .

The one - seventh power law-: In this law of turbulent, velocity variation corresponds to a much favoured velocity profile and the mean velocity increases as the one- seventh power of the distance from the boundary wall.

Geometric similarity -:Geometric similarity imples similarity of form. The model is a geometric reduction of the prototype and is accomplished by maintaining a fixed ratio for all homologous lengths between the model and the prototype. 

Kinematic similarity -: Kinematic similarity involves the scale of time as well as length.It implies similarity in motion. Kinematic simi-larity between a model and the prototype is attained if the homologous moving particles have the same velocity ratio along geo-metrically similar path.