西科斯基飞行器公司是一家美国飞机和直升机制造商。由俄罗斯裔美国飞行器工程师伊戈尔·伊万诺维奇·西科斯基于1923年创建。公司总部设在康涅狄格州的斯塔特福德市 。西科斯基设计了第一架稳定的单引擎可操纵直升机并于1942年开始大规模生产。 1934年西科斯基公司成为联合飞行器公司（现联合技术公司）下的子公司。西科斯基公司是美国的主要直升机制造商之一，目前其最著名产品为UH-60黑鹰。美国总统使用的直升机（海军陆战队一号）也一直使用西科斯基公司产品，目前海军陆战队一号机队由一架VH-3（H-3海马）和一架VH-60（UH-60黑鹰）组成。
A low-fidelity model for modeling ice accretion phenomena over two-bladed teetering rotors has been developed. In this approach, the blades are assumed to be rigid, and the flapping motion is caused by the inertial, centrifugal, and aerodynamic forces acting on the blade section. The aerodynamic forces are computed using a table look-up of precomputed airfoil lift and drag coefficients as a function of effective angle of attack. Following the analysis of the rotor without icing effects, ice shapes at selected radial locations on the rotor are computed. The impact of ice shapes on the two-dimensional (2D) lift and drag characteristics is estimated using a 2D computational fluid dynamics analysis. Finally, the rotor is reanalyzed using the low-fidelity model with the iced airfoil lift and drag characteristics. Comparisons with test data and a higher fidelity model are also presented.
In the automotive industry, Safety of the Intended Function (SOTIF, ISO 21448) is a framework to reduce unknown hazard scenarios in the operational design domain and mitigate known hazard scenarios to achieve acceptably safe system behavior. Civil aviation practices, such as ARP4754B and ARP4761A, have a similar intent. A review of ISO 21448 from an aerospace perspective will identify potential opportunities to leverage SOTIF principles to complement the above aerospace recommended practices, as well as potential conflicts between these approaches. One key aspect is the proactive identification of safety requirements and potential architectural deficiencies early in the development process. This can be especially valuable when introducing new functionalities such as autonomy where system boundaries go beyond traditional architectures, and where identifying unforeseen situations that impact safety becomes particularly challenging. The paper will identify opportunities and limitations in the application of SOTIF within the aerospace industry to address such challenges and develop systems that are inherently safer and more robust throughout the operational lifecycle.
A non-linear energy-based analytical approach to design flat sandwich panels resistant to bird strike is presented. The approach is then complemented by numerical simulation in Abaqus using smooth particle hydrodynamics to model the bird and a non-linear stress-strain model for the core material. Flat sandwich panels were designed to deform and just fail when the maximum deflections are reached for given strike energies. The panels designed with this approach were tested using gelatin birds and two different material combinations with non-toughened and toughened facesheet and core materials. The analytical and numerical approaches were found to be conservative as they predicted failure onset for the bird energies selected while the tests showed no damage. The maximum deflection and maximum strains at different locations of the panels were well predicted by the numerical analysis, but the predictions departed significantly from the tests after the first peak was reached.
