Who was investigated turbulence at first ? Is there any description of turbulence ? What is turbulence ?

Burkhart,

As my old professor, Alan Chapman at Rice University, said in his introduction to the subject,

Turbulence is a very complicated time-dependent flow.

My continuation: Beyond that, you get into fluctuations, statistical techniques, much advanced math, inferences from experiment and observation, etc. and lots of frustration. All of these are designed to remove the "very complicated" from Professor Chapman's definition.

When you're successful, you obtain a matematical description of the flow that can get useful results from a CFD code. Often you're not successful.

Tennekes and Lumley, "A First Course in Turbulence", is indeed a good place to start.

Good luck!