Calculation of the time-varying mean velocity by different methods and determination of the turbulence intensities

Bombar G., Guney M. S., Tayfur G., Elci S.

SCIENTIFIC RESEARCH AND ESSAYS, cilt.5, sa.6, ss.572-581, 2010 (SCI-Expanded) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 5 Sayı: 6
  • Basım Tarihi: 2010
  • Dergi Adı: SCIENTIFIC RESEARCH AND ESSAYS
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Sayfa Sayıları: ss.572-581
  • Anahtar Kelimeler: Unsteady flow, instantaneous velocity measurement, flow tracker, data processing
  • Dokuz Eylül Üniversitesi Adresli: Evet

Özet

The raw velocity data for both stream-wise and transversal directions in unsteady flows, which are formed by generating input hydrograph, are obtained by using a flow tracker. The same hydrograph is generated 15 times and the mean values are found by calculating the average of all hydrographs. The time varying mean is obtained by using FFT, moving average, wavelet and EMD methods. The best time varying mean is selected according to prescribed criteria. Then, the 15 time series are processed and the stream-wise and transversal turbulence intensities are obtained. The mean of the product of fluctuations is also determined.