In general, a turbulent flow will incur a lower frictional lower frictional loss
ID: 1841716 • Letter: I
Question
In general, a turbulent flow will incur a lower frictional lower frictional loss as compared to a laminar flow. The drag is solely due to the friction between the flow stream and the surface of a body immersed in the fluid If the friction factor is smaller, the pressure drop in a pipe is always smaller The mechanism of the lift generation may be explained using the Bernoulli equation. Flow through a large body may be studied using a scaled down model provided that a similarity analysis is followed. The roughness of a surface may affect the stability of a boundary layer The boundary layer separation is independent of the shape of the body. Cavitation may reduce the performance of a pump or turbine rapidly and must be avoided to maintain stable and efficient operation The trailing vortex system of a finite wing may cause induced drag, and subsequently increase the total drag significantly An angle of attack increases smoothly until a maximum is reached. Further increases in angle of attack may produce a sudden in lift and the airfoil is said to have stalled.Explanation / Answer
1. true
as the effect of friction is considered as negligible in the turbulent flow, the frictional losses are considered as negligible in case of turbulent flow compared to laminar flow.
2. true
the drag flow is mainly due to the interaction of the external fluid with the surfce of the object.
3. false
the pressure loss is dependent on the various parameters such as velocity, length, diameter etc. so, only friction factor does not predict the change in pressure loss.
4. true
the lift force was derived from the bernoullis eqn. this was majorly due to the change in the kinetic head