The ratio between the kinematic viscosity and the thermal diffusivity is called the Prandtl Number.
The Prandtl Number is a dimensionless number approximating the ratio of momentum diffusivity (kinematic viscosity) and thermal diffusivity and can be expressed asPr = v / αThe Prandtl number can alternatively be expressed asPr = μ cp / kThe Prandtl Number is often used in heat transfer and free and forced convection calculations. where:ν : kinematic viscosity, ν = μ / ρ, (SI units : m2/s)α : thermal diffusivity, α = k / (ρcp), (SI units : m2/s)μ : dynamic viscosity, (SI units : Pa s)k: thermal conductivity, (SI units : W/(m K) )cp : specific heat, (SI units : J/(kg K) )ρ : density, (SI units : kg/m3 ).answered by : eng_moom
Prandtl number is dimensionless number, denoted by Npr.Npr = Cp (viscosity)/(thermal conductivity) Cp - specific heat, J per ( Kg Kelvin) viscosity in poise (gm per( cm sec)) thermal conductivity in Watt per (meter kelvin) Prandtl number is important in heat transfer.
Correct: it is a dimensionless number.
A dimensionless number has no units. The units of all variables that compose the dimensionless number (product or ratio) must cancel each other.
If a quantity is "dimensionless", that means it has no units, and it's just a number.
32 is a pure number (integer) and is dimensionless.
Dimensionless numbers allow for comparisons between different systems without being affected by the units used. They provide insight into the physical behavior of systems and can help predict how they will respond to changes in parameters. Dimensionless numbers also help simplify complex problems and reveal underlying relationships between variables.
A dimensionless number is a quantity that is normalized as to negate the differences in properties from one substance to another. They are used to enable scientists and engineers to make direct comparisons between dissimilar substances. An example, commonly used in both Fluid Dynamics and Heat Transfer is the Reynolds number expressed as Re = density*velocity*L/mu or Re = velocity*L/nu, where L is the characteristic length, mu is the dynamic viscosity, and nu is the kinematic viscosity. Using the Reynolds number, comparisons between two dissimilar substances (e.g. Glycerine, Water, Alcohol, and Blood) can be made. The nussalt number in heat transfer is a dimenssionaless number and it is the ratio of conductive to convective heat transefer across a boundary.
A pure dimensionless (without units) number is never equivalent to a number with a unit.
0.0135
60 is a dimensionless number. An hour is a unit for measuring time.
Yes, the magnitude of a vector is a scalar.