I have a problem .

how does the transmission between laminar and turbulent.

someone who helps me.

turbulence

Do you mean where is the transition between laminar and turbulent flows? If so, to find this out, you will need to work out the dimensionless Reynolds number for the flow, which is defined as:

Re = uL/{nu}

where u is the characteristic velocity, L is the characteristic system length scale and {nu} is the kinematic viscosity of the fluid. (For example, if you are considering flow in a cylindrical pipe, u is the volumetric average velocity through the pipe and L is the pipe diameter.) For a Newtonian fluid (one with constant viscosity for all shear rates), a Reynolds number of up to 2100 indicates laminar flow, while a Reynolds number of about 10,000 or higher indicates turbulent flow: anything in between is transitional flow, which has some aspects of both kinds.