Dear Malik, in pumps a turbulent flow can give problems of low efficiency, noise and structural damage on impeller. Deposits in water can amplify the problems of structural damages: we have experienced shaft impeller break-down in the case of "hard" (Calcium richness) water. For you, at what Reynolds number happens turbulent flow?  Gianluca

Thank you for your answer Dr Gianluca Argentini

I ended up knowing these problems but my equation was about the problems of pecking in the casing due to pressure changes or   and the height of water column.  

Regards

Dr. Malik

Cavitation can be a problem in with turbulent flows in pumps and impellers which can have a negative impact on longevity of the equipment.

Thank you very much Dr. Jorg Leicher

I agree that a great problem can be in the cavitation condition. I am not aware of the existance of some device to avoid turbulent condition....

The disadvantages of turbulent flow depends on how turbulent the flow is. Cavitation, pecking on the casing, head losses are usual problems. Design modifications can be helpful to reduce its effects.

Thank you very much Dr. Kannan B T

It is a well established empirical fact that, for a given flow rate, a small concentration of fine suspended solids reduce the pressure drop due to flow. The problem is very complex. However, it has been suggested that the effect has to do with damping the rotational velocity of micro eddies/vortices (inertial effect?) in the flow field. So, in your case, depending on the concentration of suspended solids, this good effect (pressure drop reduction) could let you go to higher levels of turbulence (higher Reynolds Number) than that with pure water, for the same flow rate. However, there is an upper limit of solids concentration above which the suspension will become, possibly, a non-Newtonian Bingham plastic with a higher apparent viscosity, that is, giving a higher pressure drop.     

Thank you Dear Dr. R.P.Pecanha 

Your information to give me about my equation  was excellent and valuable

Regards

Malik N Hawas

hello

A turbulent flow can be either an advantage or disadvantage. A turbulent flow increases the amount of air resistance and noise; however, a turbulent flow also accelerates heat conduction and thermal mixing. Therefore, understanding, handling, and controlling turbulent flows can be crucial for successful product design.

from link

www.cradle-cfd.com/tec/column01/008.html