هدف: با توجه به رشد روزافزون آموزش شیوه مجازی و ویژه در شرایط گسترش پاندمی کرونایروس، نقش اساسی مدیریت کلاسی ارتقا کیفیت باید مورد قرار گیرد این پژوهش هدف تدوین مدل رابطه علّی هدفمند کلاس وضعیت روان‌شناختی پیامدهای تحصیلی دانشجویان انجام شد. روش: روش بر حسب هدف، کاربردی ماهیت از نوع توصیفی - همبستگی بود. جامعه آماری مشتمل انواع مقاطع دانشگاه­ های دولتی پیام نور شهر تهران نمونه اساس جدول مورگان ب...

ةصلاخلا Allopeas gracilis is recorded for the first time in southern Iraq. It was collected from two localities (Abu-Al Khaseeb region and Hareer region) from Basrah city. ضرلاا عقوقلا نم ةنيع نورشعو نامث ي Allopeas gracilis مت للاخ ةرصبلا ةنيدم ،ريرح ةقطنم و بيصخلا وبا ةقطنم نم اھعمج ناسين رھش 2008 راذاو 2008 يلاوتلا ىلع . ليجستلا اذھ ربتعي دعب ةرصبلا ةنيدم نم ةيضرلاا عقاوقلا نم ثلاثلا Monacha...

The complex flow physics challenges and asks questions regarding these challenges a wide range of jet flows found in aerospace engineering. Hence, the daunting task facing Reynolds-averaged Navier-Stokes (RANS) technology, for which the time average of the turbulent flow field is solved, is set out. Despite the clear potential of large eddy simulation (LES)-related methods and hybrid forms invo...

A consistent dual-mesh hybrid LES/RANS framework for turbulence modeling has been proposed recently (H. Xiao, P. Jenny, A consistent dual-mesh framework for hybrid LES/RANS modeling, J. Comput. Phys. 231 (4) (2012)). To better enforce componentwise Reynolds stress consistency between the LES and the RANS simulations, in the present work the original hybrid framework is modified to better exploi...

Flow characteristics are presented of simulation results of plane impinging jets at high nozzle-plate distances, with two k-ω based hybrid RANS/LES (Reynolds Averaged Navier–Stokes/Large–Eddy Simulation) models and a k-ω RANS model. The first hybrid RANS/LES model is obtained by substitution of the turbulent length scale by the local grid size in the destruction term of the turbulent kinetic en...

The aerodynamic performance of a cylinder Pitot probe for velocity measurements in compressible non-ideal gas flows, such as those encountered Organic Rankine Cycle (ORC) turbines, is investigated by means Computational Fluid Dynamics. Numerical simulations are performed at subsonic and transonic conditions, freestream Reynolds numbers the critical regime. working fluid organic vapour Novec™ 64...

The increasing introduction of renewable energy capacity has changed the perspective operation conventional power plants introducing necessity reaching extreme off-design conditions. There is a strong interest in development and optimization technologies, that can be retrofitted to an existing plant enhance flexibility, as well increase performance lower emissions.Under framework European proje...

The seminar discusses basic concepts of turbulence modeling in computational fluid dynamics (CFD). There are two mainstreams present in the field of interest. The first one are so called Reynolds averaged Navier-Stokes (RANS) models. RANS models are most widely used nowadays. Therefore theoretical aspects of RANS models are presented in more detail. The second mainstream presents direct numeric...