| Titre : | Behavior of unsteady turbulent starting round jets (2012) |
| Auteurs : | Neerav Abani, Auteur ; Jaal B. Ghandhi, Auteur |
| Type de document : | Article : texte imprimé |
| Dans : | Transactions of the ASME . Journal of fluids engineering (Vol. 134 N° 6, Juin 2012) |
| Article en page(s) : | 08 p. |
| Note générale : | fluids engineering |
| Langues : | Anglais |
| Index. décimale : | 620.1 (Essais des matériaux. Défauts des matériaux. Protection des matériaux) |
| Tags : | turbulent starting jets ; injection ; high-speed schlieren imaging |
| Résumé : | Turbulent starting jets with time-varying injection velocities were investigated using high-speed schlieren imaging. Two solenoid-controlled injectors fed a common plenum upstream of an orifice; using different upstream pressures and actuation times, injection-rate profiles with a step increase or decrease in injection velocity were tested. The behavior of the jet was found to be different depending on the direction of the injection-velocity change. A step increase in injection velocity resulted in an increased rate of penetration relative to the steady-injection case, and a larger increase in injection velocity resulted in an earlier change in the tip-penetration rate. The step-increase data were found to be collapsed by scaling the time by a convective time scale based on the tip location at the time of the injection-velocity change and the difference in the injection velocities. A sudden decrease in injection velocity to zero was found to cause a deviation from the corresponding steady-pressure case at a time that was independent of the initial jet velocity, i.e., it was independent of the magnitude of the injection-velocity change. Two models for unsteady injection from the literature were tested and some deficiencies in the models were identified. |
| DEWEY : | 620.1 |
| ISSN : | 0098-2202 |
| En ligne : | http://asmedl.org/getabs/servlet/GetabsServlet?prog=normal&id=JFEGA4000134000006061202000001&idtype=cvips&gifs=Yes&ref=no |
