رسالة جامعية
Διερεύνηση τυρβώδους ορθογωνικής δέσμης εκροής ; Investigation of rectangular turbulent jet
| العنوان: | Διερεύνηση τυρβώδους ορθογωνικής δέσμης εκροής ; Investigation of rectangular turbulent jet |
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| المؤلفون: | Cavo, Aleksander |
| بيانات النشر: | University of Patras Πανεπιστήμιο Πατρών |
| سنة النشر: | 2008 |
| المجموعة: | National Archive of PhD Theses (National Documentation Centre Greece) |
| مصطلحات موضوعية: | Ορθογωνική δέσμη εκροής, Τυρβώδης δέσμη, Επίπεδη δέσμη, Στρώματα μίξης, Δέσμη εκροής, Ελεύθερες δέσμες, Turbulent jet, Planar jet, Mixing layers, Free jet, Επιστήμες Μηχανικού και Τεχνολογία, Επιστήμη Μηχανολόγου Μηχανικού, Engineering and Technology, Mechanical Engineering |
| الوصف: | In the present work the three-dimensional velocity and vorticity vector fields in the near field of the rectangular turbulent jet with aspect ratio 6 have been experimentally investigated. Turbulent rectangular jets are prototypical free shear flows of practical interest in propulsion, combustion and environmental flows. The presented data, consisting of distributions of mean and statistical characteristics of components of the two fields at several locations within the jet’s near field region, were obtained by using an in-house constructed 12-sensor hot wire probe consisting of three closely separated orthogonal 4-hot wire velocity arrays. The probe measures the three components of velocity simultaneously at three closely spaced locations. Spatial velocity derivatives are estimated using a forward difference scheme of first order accuracy. Streamwise velocity derivatives are estimated using Taylor’s frozen turbulence hypothesis. 12-sensor construction and measurement technique relies upon previous work of Lemonis & Dracos (1995) and Lemonis (1995) and has been further improved and refined at Laboratory of Applied Thermodynamics of the University of Patras. Measurements have been conducted in a jet with Reynolds number ReD = 21000 at nozzle distances, x/D =1, 3, 6 and 11, where D is the width of the nozzle. The performance of 12-sensor probe is investigated in comparison with X-sensor probe measurements. Results referring to measurements of velocity with both sensors are in good agreement, except in locations where the steep velocity gradients and the three dimensionality of the velocity field undermine X-wire probe measurements. The statistical properties of the velocity-vorticity fields based on measurements with the sensor probe are presented in comparison with several experimental and direct numerical simulation data of other researchers. Distributions of fluctuating velocity –vorticity fields show that in the potential core region the values are low on the centerline of the jet and quite high in the ... |
| نوع الوثيقة: | doctoral or postdoctoral thesis |
| اللغة: | Greek, Modern (1453-) |
| العلاقة: | http://hdl.handle.net/10442/hedi/17545Test |
| DOI: | 10.12681/eadd/17545 |
| الإتاحة: | https://doi.org/10.12681/eadd/17545Test http://hdl.handle.net/10442/hedi/17545Test |
| رقم الانضمام: | edsbas.CAAC582F |
| قاعدة البيانات: | BASE |
| DOI: | 10.12681/eadd/17545 |
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