Effect Of Manufacturing Tolerance In Flow Past A Compressor Blade

This paper presents the effect of manufacturing tolerance on performance and stability boundaries of a transonic fan using a RANS simulation. The effect of tip gap and stagger angle was analysed through a series of single passage and double passage simulation; based on which an optimal arrangement was proposed for random tip gap and random stagger angle in case of a whole annulus rotor. All simulations were carried out using NASA rotor 67 as a test case and AU3D an in-house CFD solver. Results illustrate that the stagger angle mainly affects efficiency and hence its circumferential variation must be as smooth as possible. Furthermore, the tip gap affects the stability boundaries, pressure ratio and efficiency. Hence its optimal configuration mandates that the blades be configured in a zigzag arrangement around the annulus i.e. larger tip gap between two smaller ones.

Comprehensive Analysis On A New Type VR-Resolver with Toroidal Windings Under Healthy and Eccentric Cases

<div>A novel analysis for a new type Variable Reluctance Resolver (VR-Resolver) with toroidal windings is presented in this work. The resolver with various windings configurations as well as different rotor structures is considered for analysis. Position error of the resolvers in both healthy and eccentric cases are studied, where the effect of the eccentricity fault is analyzed for the resolvers with various windings configuration and rotor shapes. Hence, the analysis of the manufacturing tolerance due to the eccentric rotor is obtained by several analyses. Noticing the Magnetic Equivalent Circuit (MEC) method’s flexibility as well as in regards to the analysis of the several structures, a well-known flexible MEC-based method with adjustable accuracy is considered for modeling. Hence shorter processing time and more flexibility compared to Finite-Element-Method (FEM) are needed. Finally, the effectiveness of the presented works is proved by the performed validation via both FEM and experimental results.</div>

Comprehensive Analysis On A New Type VR-Resolver with Toroidal Windings Under Healthy and Eccentric Cases

<div>A novel analysis for a new type Variable Reluctance Resolver (VR-Resolver) with toroidal windings is presented in this work. The resolver with various windings configurations as well as different rotor structures is considered for analysis. Position error of the resolvers in both healthy and eccentric cases are studied, where the effect of the eccentricity fault is analyzed for the resolvers with various windings configuration and rotor shapes. Hence, the analysis of the manufacturing tolerance due to the eccentric rotor is obtained by several analyses. Noticing the Magnetic Equivalent Circuit (MEC) method’s flexibility as well as in regards to the analysis of the several structures, a well-known flexible MEC-based method with adjustable accuracy is considered for modeling. Hence shorter processing time and more flexibility compared to Finite-Element-Method (FEM) are needed. Finally, the effectiveness of the presented works is proved by the performed validation via both FEM and experimental results.</div>

Beam generator of 4-channel with zeroth order suppressed by reflective T-type grating

Four-port beam splitter with good uniformity was proposed by T-type double-layer with different dielectric grating. The total efficiency of the beam splitter is over 90% with beam splitting uniformity better than 3%. At the same time, the simplified modal analysis is added to calculate the grating mode and effective refractive index of the grating area, which clearly describes the physical propagation mechanism inside the grating. The finite element method is used to investigate the normalized field of the grating, which more intuitively reflects the way of energy transfer inside the grating. Finally, the incident characteristics and manufacturing tolerance of the grating are analyzed. Properties of the T-type grating were analyzed in three methods, which more fully illustrates the applicability and stability of the grating in this paper.

Improved uncertain method for safety analysis of aircraft landing gear

There are various uncertain factors in most practical engineering applications, such as input loads, structural sizes, manufacturing tolerance, and initial and boundary conditions. The interval method and grey number theory are common methods to deal with uncertainty. In this article, the interval truncation method and grey number theory are improved. And a mixed method is proposed to represent the confidence interval of output result based on the improved interval truncation method and improved grey number theory. The proposed methods’ feasibility is verified by a stepped bar; the methods are applied to the analysis of aircraft landing gear safety uncertainty.

Transonic Fan Blade Redesign Approach to Attenuate Nonsynchronous Vibration

Due to manufacturing tolerance and deterioration during operation, different blades in a fan assembly exhibit geometric variability. This leads to asymmetry which will be amplified in the running geometry by centrifugal and aerodynamic loads. This study investigates a phenomenon known as Alternate Passage Divergence (APD), where the blade untwist creates an alternating pattern in passage geometry and stagger angle around the circumference. After the formation of alternating tip stagger pattern, APD's unsteady effect, APD-induced Non-Synchronous Vibration (APD-NSV), can cause the blades from one group to switch to the other creating a travelling wave pattern around the circumference. Thus, it can potentially lead to high cycle fatigue issues. More importantly, this phenomenon occurs close to, or at, peak efficiency conditions and can significantly reduce overall efficiency. Therefore, it is vital to attenuate the NSV behaviour. In this study, an redesign approach is investigated.

UCsim2: 2D Structured Illumination Microscopy using UC2

State-of-the-art microscopy techniques enable the imaging of sub-diffraction barrier biological structures at the price of high-costs or lacking transparency. We try to reduce some of these barriers by presenting a super-resolution upgrade to our recently presented open-source optical toolbox UC2. Our new injection moulded parts allow larger builds with higher precision. The 4x lower manufacturing tolerance compared to 3D printing makes assemblies more reproducible. By adding consumer-grade available open-source hardware such as digital mirror devices (DMD) and laser projectors we demonstrate a compact 3D multimodal setup that combines image scanning microscopy (ISM) and structured illumination microscopy (SIM). We demonstrate a gain in resolution and optical sectioning using the two different modes compared to the widefield limit by imaging Alexa Fluor 647- and SiR-stained HeLa cells. We compare different objective lenses and by sharing the designs and manuals of our setup, we make super-resolution imaging available to everyone.