湍流射流的PIV研究
Turbulent jets have been always present in fluid-mechanic researches due to thelarge number of applications they have and to the presence of all the turbulence featureson them. Thanks to the use of relative new non-intrusive techniques–such as PIV(Particle Image Velocimetry)-, the knowledge of turbulence in general, and turbulentjets in particular has increased.This work is focused on the assessment of both, the main characteristics of theturbulent jet and, at the same time, some significant PIV features. For that aim twoexperiments are proposed:-The first one, denominated “Spatial Resolution in PIV”, tries to determine thebest position to place the digital camera that films the movement of the particlespresent in the jet, taking into account that we are interested on studying not onlythe microscales of the turbulent flow, but also the velocity field and therecovering of isotropy by evaluating the turbulent parameters (skewness,kurtosis, square mean derivative ratios,…).-In the second one, called “Effect of the Reynolds Number in Turbulence”,starting from the results of the first experiment, the behavior of the jet dependingon the relationship between the inertia forces and the viscous ones is analyzed.To do this, three different zones along the jet and eight different Reynoldsnumbers are to be studied.This report is structured in four different chapters. The first one corresponds to atheoretical introduction to turbulence. In the second one the experimental setup isdescribed after introducing the PIV measurement technique. The third one presents theresults and carries out a deep analysis of them. Finally, in chapter four, the results aresummarized obtaining some important conclusions and considering as well futurechallenges of the present work.