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| 1 | Profile and Secondary Flow Losses in a High-Lift LPT Blade Cascade at Different Reynolds Numbers under Steady and Unsteady Inflow Conditions显示文摘The aerodynamic flow field downstream of a Low-Pressure High-Lift(HL)turbine cascade has been experimentally investigated for different Reynolds numbers under both steady and unsteady inflows,in order to analyse the cascade performance under real engine operating conditions.The Reynolds number has been varied in the range 100000 | Satta F. Simoni D. Ubaldi M. Zunino P. Bertini F. | 2012 | Journal of Thermal Science2012，21，6： | 5 |
| 2 | Experimental Investigation of Flow Instabilities in a Laminar Separation Bubble显示文摘The present paper reports the results of a detailed experimental study aimed at investigating the dynamics of a laminar separation bubble, from the origin of separation up to the breakdown to turbulence of the large scale coherent structures generated as a consequence of the Kelvin-Helmholtz instability process. Measurements have been performed along a flat plate installed within a double contoured test section, designed to produce an adverse pressure gradient typical of Ultra-High-Lift turbine blade profiles, which induces the formation of a laminar separation bubble at low Reynolds number condition. Measurements have been carried out by means of complementary techniques: hot-wire(HW) anemometry, Laser Doppler Velocimetry(LDV) and Particle Image Velocimetry(PIV). The high accuracy 2-dimensional LDV results allow investigating reverse flow magnitude and both Reynolds normal and shear stress distributions along the separated flow region, while the high frequency response of the HW anemometer allows analyzing the amplification process of flow oscillations induced by instability mechanisms. PIV results complement the flow field analysis providing information on the generation and evolution of the large scale coherent structures shed as a consequence of the separated shear layer roll-up, through instantaneous velocity vector maps. The simultaneous analysis of the data obtained by means of the different measuring techniques allows an in depth view of the instability mechanisms involved in the transition/reattachment processes of the separated shear layer. | Simoni D. Ubaldi M. Zunino P. | 2014 | Journal of Thermal Science2014，23，3： | 4 |
| 3 | Free-stream Turbulence Effects on the Boundary Layer of a High-lift Low-Pressure-Turbine Blade显示文摘The suction side boundary layer evolution of a high-lift low-pressure turbine cascade has been experimentally investigated at low and high free-stream turbulence intensity conditions.Measurements have been carried out in order to analyze the boundary layer transition and separation processes at a low Reynolds number,under both steady and unsteady inflows.Static pressure distributions along the blade surfaces as well as total pressure distributions in a downstream tangential plane have been measured to evaluate the overall aerodynamic efficiency of the blade for the different conditions.Particle Image Velocimetry has been adopted to analyze the time-mean and time-varying velocity fields.The flow field has been surveyed in two orthogonal planes(a blade-to-blade plane and a wall-parallel one).These measurements allow the identification of the Kelvin-Helmholtz large scale coherent structures shed as a consequence of the boundary layer laminar separation under steady inflow,as well as the investigation of the three-dimensional effects induced by the intermittent passage of low and high speed streaks.A close inspection of the time-mean velocity profiles as well as of the boundary layer integral parameters helps to characterize the suction side boundary layer state,thus justifying the influence of free-stream turbulence intensity on the blade aerodynamic losses measured under steady and unsteady inflows. | Simoni D. Ubaldi M. Zunino p. Ampellio E. | 2016 | Journal of Thermal Science2016，25，3： | 0 |
| 4 | 冻融后的完整胚胎与局部损伤的冻融胚胎采用激光辅助孵化技术去除坏死的卵裂球及进行选择后潜在存活能力的比较显示文摘Objective: Partially damaged frozen and thawed embryos are currently considered to have a lower viability than intact ones. This study was undertaken to compare the performance of intact frozen and thawed embryos with that of partially damaged embryos after removal of the necrotic blastomeres. Design: Observational clinical series. Setting: Private hospital. Patient(s): Three hundred twenty-six infertile couples undergoing frozen embryo transfer. Intervention(s): Removal of necrotic blastomeres from frozen-thawed human embryos. Main Outcome Measure(s): Pregnancy and implantations rates. Result(s): Outcomes of frozen embryo transfer cycles in which all embryos were fully intact (group 1) were compared with those in which all embryos have lost 1-2 blastomeres (group 2) or 3-4 blastomeres (group 3). Laser-assisted hatching was performed in all embryos, and necrotic blastomeres were removed from partially damaged embryos on this occasion. Only embryos that resumed mitotic activity after thawing were transferred. Comparable clinical pregnancy rates (PR) (38.7%, 39.6%, and 29.4%), delivery rates (34.4%, 34.0%, and 29.4%), and implantation rates (21.6%, 21.4%, and 17.2%) were obtained in groups 1, 2, and 3, respectively. Conclusion(s): The developmental potential of partially damaged frozen and thawed embryos can be equivalent to fully survived embryos if the necrotic blastomeres are removed from the partially damaged embryos and only those of them that show post-thaw cleavage are selected for transfer. | Rienzi L. Ubaldi F. Iacobelli M. 张剑萍 | 2006 | 世界核心医学期刊文摘(妇产科学分册)2006，0，2： | 0 |
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