Optimizing Effect of Wavy Leading Edge (WLE) in Rectangular Wing and Taper Wing

Experimental and numerical research have been performed to investigate the Wavy Leading Edge (WLE) effect on the rectangular wing. The WLE is inspired by humpback whale flipper morphology which is blunt and rounded in certain form pattern. This flipper shape plays an important role for its behaviour specially capturing their prey. This advantage could be applied to other systems such as fin stabilizers or wind turbines. Steady cases in various aspect ratios were conducted to find out the optimum effect of WLE with baseline NACA 0018 profile at Reynolds number 1.4 x 105. The chord length of the wing (c) was 125 mm. The WLE shape defined as wavelength (W) 8% of c and amplitude (d) is 5% of c. The aspect ratio (AR) variations were 1.6; 3.9; 5.1; 7.9 and 9.6.  A simple rectangular form of the wing was selected to analysis the WLE effect on the various ARs. The taper wing shape is applied to find out the WLE effect at the AR 7.9. three types of taper ratio (TR) are 0.1; 0.3 and 0.5. The results show that the WLE on the taper wing has better advantage to control the stall in steady case. Another impressive result was the WLE wing with AR 7.9 and TR 0.3 has the best lift coefficient and pressure distribution.Keywords: stall, wavy leading edge, steady case, rectangle wing, taper wing, aspect ratio.

Model refinements and experimental testing of highly flexible piezoelectric energy harvesters

This paper addresses limitations to existing analytical models for piezoelectric energy harvesters. The presented model is targeted at predicting behaviours of highly flexible piezoelectric devices (FPEDs) and includes high orders of substrate and piezoelectric material nonlinearity, geometric nonlinearity, and additionally the effects of both self-weight and pre-stress. Validation through experimental testing is provided. The influence of self-weight on vibratory dynamics becomes important in FPEDs due to both material composition and dimension. The developed model facilitates the simulation of FPED performance mounted at specified angles to the horizontal. In one study, for a FPED of 120 mm in length, the resonant frequency changed by over 30 percent with mounting angle. Consideration of mounting orientation is advised as self-weight increases damping and significantly lowers FPED performance – over a 50 percent reduction in one presented case

Predicting the Motions of a Fishing Boat Caused by Improving the Stern Part using a Hybrid Particle-Grid Scheme

Improving a ship’s stern part could help to reduce greenhouse gases and costs. However, a ship sailing in actual conditions experiences disturbances that can affect its performance. Ship performance is an important aspect of the design process that guarantees ship safety. The heave and pitch motions of an improved fishing boat were predicted numerically by using a hybrid scheme of Eulerian grid-Lagrangian particle, hereinafter improving its stern part and attaching an additional part. The stern part improvement and additional structure attachment affected an increase on the heave amplitude from the ship’s basic form by 5% to 10%. Moreover, the improvement of the stern part in the bottom area contributed to a better heave amplitude than that of the side area. Finally, the pitch amplitude for all forms was relatively small and affected an increase of 5% to 9%, dependent on the form. The improvement had a greater effect on heave motion than pitch

Novel bronchofiberscopic catheter spray device allows effective anesthetic spray and sputum suctioning

AbstractStudy objectives: To evaluate how serum lidocaine concentrations (SLC) rise when lidocaine is administered by a Bronchofiberscopic Catheter Spray Device (BCSD), and to demonstrate the effect on the aspiration speed of a substitute for sputum when a catheter spray remains in the channel of the bronchofiberscope (BF).Methods: This is a prospective randomized clinical study. After lidocaine ultrasonic nebulizer, the BF was inserted orally. During the procedure patients received 4% lidocaine by two methods. In Group 1, 11 patients received lidocaine by bronchofiberscopic (BF) injection. In Group 2, 15 patients received lidocaine by spraying from the ∅1.06mm catheter through the BF channel. SLC were measured at 40min from onset of nebulization. Separately, we examined how effectively sputum was aspirated through the BF channel with a catheter.Results: Total lidocaine dose (TLD) is the total dose used for nebulization and for the BF injection or spray. The TLD for Groups 1 and 2 were 698.2±162.1mg (mean±sd) and 498.7±103.8mg, respectively (P=0.03). The SLC for Groups 1 and 2 were 1.28±0.72 and 1.48±0.70mg/l, respectively (P=0.49).Conclusions: Using BCSD allows easier in administration of lidocaine and is not associated with a significant increase in SLC in comparison with BF injection. Although sputum aspiration using the BF inserted with our catheter was somewhat slow, we did not feel inconvenient so much. Compared to the conventional method, using BCSD may be preferable for patients and bronchoscopists

Impressive clinical course of diabetic patient with various medical problems and remarkable improvement by insulin degludec and liraglutide (Xultophy)

Diabetes mellitus causes macrovascular, microvascular angiopathy, and increased cancer risk. Authors et al. have continued clinical practice and research on diabetes cases. Current case is impressive 79-year-old female with various diseases. They include asthma and COPD, steroid intake for years, sleep apnea syndrome (SAS), Continuous Positive Airway Pressure (CPAP) therapy, tongue cancer, arteriosclerosis, bone complications, Carpal tunnel syndrome (CTS), and so on. When she developed hyperglycemia with 9.0% of HbA1c, Xultophy® was started. It contains insulin degludec and liraglutide which is Glucagon-like peptide-1 receptor agonist (GLP-1 RA). HbA1c values decreased as 7.9%, 7.3%, 6.9%, 6.5% in 1-4 months, with remarkable effect. The satisfactory efficacy may be from double agents of Xultophy® or probable secondary diabetes due to continuation of steroid of the case. This report will be expected to be some reference in the future diabetic research development

Simply-supported multi-layered beams for energy harvesting

This paper develops an analytical model for predicting the performance of simply-supported multi-layered piezoelectric vibrating energy harvesters. The model includes the effects of material and geometric nonlinearities, as well as axial pre-tension/compression, and is validated against experimental devices for a large range of base accelerations. Numerical and experimental investigations are performed to understand the benefits of using simply supported devices compared to cantilevered devices. Comparisons are made in an unbiased manner by tuning the resonant frequency to the same value by modifying the geometry, and the results obtained indicate that simply supported devices are capable of generating higher voltage levels than cantilever devices. The model is also used to investigate the benefits of using multi-layered devices to improve power density. Depending on harvester composition, power-per-unit-volume of piezoelectric material for a device is increased through the stacking of layers

Highly directionally spread, overturning breaking waves modelled with Smoothed Particle Hydrodynamics: A case study involving the Draupner wave

Wave breaking in the ocean affects the height of extreme waves, energy dissipation, and interaction between the atmosphere and upper ocean. Numerical modelling is a critical step in understanding the physics of wave breaking and offers insight that is hard to gain from field data or experiments. High-fidelity numerical modelling of three-dimensional breaking waves is extremely challenging. Conventional grid-based numerical methods struggle to model the steep and double-valued free surfaces that occur during wave breaking. The Smoothed Particle Hydrodynamics (SPH) method does not fall prey to these issues. Herein, we examine the SPH method's ability to model highly directionally spread overturning breaking waves by numerically reproducing the experiments presented in McAllister et al. (2019). We find that the SPH method reproduces the experimental observations well; when comparing experimental and numerical measurements we achieve coefficient of determination values of 0.92−0.95, with some smaller-scale features less well reproduced owing to finite resolution. We also examine aspects of the simulated wave's geometry and kinematics and find that existing breaking criteria are difficult to apply in highly directionally spread conditions.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Environmental Fluid Mechanic