![]() ![]() Newtonian fluids are those with constant viscosity.As a result, it is critical to comprehend the physical scenario in order to prevent making incorrect predictions. In the case of Newtonian fluids, the Reynolds number also predicts the viscous behavior of the flow.While the essential Reynolds number for turbulent flow in a pipe is 2000, the critical Reynolds number for turbulent flow over a flat plate when the flow velocity equals the free-stream velocity ranges between 10 5 and 10 6.The crucial Reynolds number is an expression of the value used to define the transition between zones, which varies depending on the kind of flow and shape.The Reynolds number’s application varies based on fluid flow characteristics such as density variation (compressibility), viscosity fluctuation (Non-Newtonian), internal or exterior flow, and so on.In case of a circular pipe, the inside pipe diameter is equal to the hydraulic diameter This means that the wetted perimeter does not include the length of the channel that is exposed to air. The entire perimeter of all channel walls in contact with the flow is the wetted perimeter of a channel. Where A represents the cross-sectional area and.The hydraulic diameter, D H, is assumed to be the typical size for internal-flow circumstances for forms such as squares, rectangular, or circular ducts when the height and width are equivalent. ρ is the density of the fluid flowing through a pipe in kg/m 3.μ is the dynamic viscosity of fluid measured in N.u is the mean velocity of flowing fluid.A is the cross-sectional area of the pipe in m 2.Q is the fluid’s volumetric flow rate measured in m 3/s.D H is the hydraulic diameter – it is generally taken for non-circular pipes.When fluid is flowing through a pipe there is a difference in the pattern of fluid flow, it can be smooth that is laminar or filled with eddies that are turbulent this can be defined in Reynolds number format as follows: Reynolds Number Fluid Flow in Pipe (Closed Channel) Hence, we can say that the Reynolds number is a unitless property. Unit of Reynolds Number = kg x m x m x m.s/(m 3 x s x kg).Unit of Reynolds Number = (kg/m 3) x (m/s) x m / (kg/m.s).Unit of Reynolds Number = units of ρ x unit of u x unit of D / unit of μ Now, let’s try to find out the units of Reynolds number! The relationship between dynamic and kinematic viscosity is given by: ν = μ/ρ Reynolds Number Unitsįrom the formula of Reynolds Number, we can write, Re = ρuD/μ ν: is the kinematic viscosity in (m 2/s).μ: is the dynamic viscosity of the flowing fluid in Pascal – seconds or N-s/m 2 or kg/m.s.D: is the length through which the fluid flow in (m).u: is the velocity of fluid flow in (m/s).ρ: is the density of flowing fluid in (kg/m 3).Re = Density x Density x Velocity / Viscous Force.Reynolds number definition equation formulaįrom the definition of Reynolds Numbers, Re = Inertial force / Viscous force ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |