Open AccessExperiments on the generation of internal wavesby a hemispheroid in a linearly stratified fluid
Author(s) -
Wei Gang,
Nengyou Wu,
Xiaogang Xu,
Su Xiao-Bing,
Yancheng You
Publication year - 2011
Publication title -
wuli xuebao
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.199
H-Index - 47
ISSN - 1000-3290
DOI - 10.7498/aps.60.044704
Subject(s) - froude number , internal wave , flume , mechanics , towing , physics , wave flume , wake , optics , wave propagation , breaking wave , flow (mathematics) , automotive engineering , engineering
Experiments are conducted to examine the characteristics of internal waves generated by a towing hemispheroid model alongside the side wall of stratified fluid flume with a linear density distribution. By the measured results with multi-channel conductivity arrays, the wave patterns, the vertical displacement and the correlation velocity for such internal waves are analyzed. Two distinct types of internal waves are obtained in experiments. One is the body-generated internal wave by the steady source with respect to the hemispheroid model, and the other is the wake-generated internal wave by the unsteady source. The transition between these two types of internal waves occurs at a critical Froude number of FrS=1.6. The corresponding comparison with towing spheroid model experiments is carried out. It follows that the number FrS is about 2/3 that of the spheroid and that the transition is more rapid and its borderline is more clear-cut than those of the spheroid modes. The body-generated internal waves of both experimental models have identical characteristics, but the draining-water volume is about 2/3 that of the spheroid model. Their wake-generated internal waves possess similar variation tendencyies, but their wave speed is about 2/3 that of the spheroid model . It also proves that this mirror-image experimental method in the flume can increase the effective range of spatio-temporal evolvement of body-generated internal waves.