# Chemical Engineering - Fluid Mechanics - Discussion

2.

Laminar flow of a Newtonion fluid ceases to exist, when the Reynolds number exceeds

 [A]. 4000 [B]. 2100 [C]. 1500 [D]. 3000

Explanation:

No answer description available for this question.

 Niki said: (Jun 7, 2012) For laminar flow, Re should be equal to or less than 2100.

 Vishwas said: (Jun 28, 2012) Laminar flow is less than or equal to 2100.

 Chitta said: (Aug 16, 2012) The above question doesn't mention about the system. we have two type of value for laminar. 1. for circular pipe----- Re<= 2100 2. for flat plate ------- Re<= 5*10^5

 B.Nath said: (Dec 8, 2012) For flow in a conduit: Re<2100 Laminar Flow, Sheer Stress depends on viscosity but not on density. 21004000 Turbulent flow depends on density.

 Jyoti said: (Mar 22, 2013) This is true only in case of flow through pipes. we cannot generalize this for every case. Re num is different for every case.

 Kalaivani said: (Aug 7, 2013) For Laminar flow, Reynold's number is less than or equal to 1(Re <= 1).

 Dhruvin Virani said: (Sep 17, 2013) Laminar flow is less than or equal to 2100. And Re>4000 Turbulent flow.

 Jayamsuba said: (Jul 24, 2014) For open channel flow, If Re <500 or 600. laminar > 2000 or 2100. turbulent. Here, Re=rho*v*R/mu...R=hydraulic gradient. For circular pipe flow, If Re <2000. laminar. > 4000. turbulent. Here, Re=rho*v*d/mu...d=dia of pipe. Here both formulae are important to keep in mind. because sometime this may confuse you.

 Khawal said: (Sep 13, 2014) Laminar flow is in linear motion and having re less than 2100, after increase the re the turbulence is so that velocity increase.

 Rajisha said: (Dec 26, 2014) Re below 2100 is laminar flow in case of circular pipes.

 Surya Teja said: (Sep 14, 2016) Let is assume the question is for circular pipe based on options given. But, the question is when will the Laminar flow cease? I think, once the fully turbulent flow is achieved, which is after crossing Re 4000. Then only we can say there is no laminar flow.

 Mahone said: (Apr 19, 2017) For circular pipes, the Reynolds number is used to classify flows as follows. <2000 laminar flow. 2000-4000. Transitional flow. >4000 turbulent flow.

 Sanjeev Gupta said: (Oct 19, 2019) Laminar flow equal and less than 2100 Reynolds number.