Why Study Turbulence

The principal goal of turbulence research is to place turbulent flows on as sound a footing as we now have for laminar flows. For laminar flows we can start with Newton s laws of motion (generally in the form of the Navier-Stokes equations in Sec. 7.9), and from a description of the flow boundaries and the 

Turbulence theories are not so far advanced that they allow us to extrapolate experimental data or to calculate flows around new shapes. Rather, turbulence specialists have concentrated on trying to reproduce the existing experimental data from some kind of comprehensive theory. This has not yet been accomplished. However, the partial results and partial understandings of turbulent flow have been useful in predicting the results of some experiments, e.g., turbulent boundary layers, as discussed in Sec. 11.5. 

One of the first historical examples in which turbulence research proved very useful was in the comparison of wind tunnel tests with the corresponding results in free flight. The early experimental work in this field indicated that results from one wind tunnel did not necessarily agree with those from another wind tunnel or with the results for free flight. These differences ultimately were explained by the study of the differences in turbulence between various wind tunnels. Some of the first careful measurements of turbulence were made to explain these contradictory wind tunnel results [3]. 

although the study of turbulence is difficult and the large efforts expended have not resulted in general or comprehensive results, the potential benefits of such a thorough knowledge of turbulence are great enough to justify the effort. 

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