What is the laminar flow between two parallel plates?
2.4. Case 1: Fluid flowing between two stationary parallel plates.
When the fluid flows between two parallel plates under viscous flow conditions the ratio of maximum velocity to average velocity is?
Explanation: For a fully developed laminar viscous flow through a circular pipe, the maximum velocity is equal to twice the average velocity. For the fully developed laminar flow through the parallel plates, the maximum velocity is equal to the (3/2) times of the average velocity.
What causes flow separation?
Separation occurs due to an adverse pressure gradient encountered as the flow expands, causing an extended region of separated flow. The part of the flow that separates the recirculating flow and the flow through the central region of the duct is called the dividing streamline.
What is the shear stress between two parallel fixed plates?
In a laminar flow between two fixed plates held parallel to each other at a distance d, the shear stress is: 1) Maximum at plane away from each plate and zero at the plate boundaries.
How is Reynolds number defined as *?
The Reynolds number (NRe) is defined as the ratio of fluid momentum force to viscous shear force. The Reynolds number can be expressed as a dimensionless group defined as. (11.5)
How are fluids classified?
Classification of fluids Newtonian fluids follow Newton’s law of viscosity and may be called viscous fluids. Fluids may be classified by their compressibility: Compressible fluid: A fluid that causes volume reduction or density change when pressure is applied to the fluid or when the fluid becomes supersonic.
When laminar flow is flowing between two parallel plates then the ratio of maximum velocity to average velocity is given by?
For the fully developed laminar flow through the parallel plates, the maximum velocity is equal to the (3/2) times of the average velocity.
What is Newton’s law of viscosity?
Newton’s Law of Viscosity. • Newton’s law of viscosity states that. “Shear stress is directly proportional to velocity. gradient”
When pipes are connected in parallel?
When two or more pipes are connected, as shown in Fig. 36.3, so that the flow divides and subsequently comes together again, the pipes are said to be in parallel.
What is attached flow?
Attached flow is the flow which has not separated from the body. For example in an airfoil, at low angles of attack the flow is attached ie the streamlines are such that they “stick” to the body.
What is laminar flow of a liquid?
laminar flow, type of fluid (gas or liquid) flow in which the fluid travels smoothly or in regular paths, in contrast to turbulent flow, in which the fluid undergoes irregular fluctuations and mixing.
What is the relation between viscosity and shear stress?
The property of a fluid to resist the growth of shear deformation is called viscosity. The form of the relation between shear stress and rate of strain depends on a fluid, and most common fluids obey Newton’s law of viscosity, which states that the shear stress is proportional to the strain rate: τ = µ dγ dt .
When is flow of viscous fluid between two parallel porous plates presented?
In the above analysis a class of solution of flow of viscous fluid between two parallel porous plates with bottom injection and top suction is presented when a cross flow velocity along the boundary is uniform, the convective acceleration is linear and the flow is deriven from pressure gradient. [1.]
When does the flow between parallel plates become laminar?
The nature of the flow (laminar vs. turbulent) not only depends on its velocity but also its density, viscosity and length scale. For flow between parallel plates, the flow is laminar when Re < 1,400; whereas for pipe flow, the flow is laminar when Re < 2,100.
How is Couette flow used in physics class?
Simple Couette configuration using two infinite flat plates. Couette flow is frequently used in undergraduate physics and engineering courses to illustrate shear-driven fluid motion. A simple configuration corresponds to two infinite, parallel plates separated by a distance ; one plate translates with a constant relative velocity
How is the flow of fluid related to shear strength?
The motion in Figure 3 is like a continuous shearing motion. Fluids have zero shear strength, but the rate at which they are sheared is related to the same geometrical factors A and L as is shear deformation for solids. Figure 3. The graphic shows laminar flow of fluid between two plates of area A. The bottom plate is fixed.