A computational analysis of vortex-shedding-induced vibration of a flexible splitter plate behind a cylinder at a low Reynolds number is conducted to understand effects of the length and flexibility of a splitter plate on the drag and lift of a cylinder and vibration of the attached plate. The drag and lift coefficients, the Strouhal number of vortex shedding, and the magnitude of tip displacements of a flexible splitter plate are found to be intricate functions of the plate flexibility. The deflection shape of a flexible splitter plate is dependent on the length of the plate, while the deflection magnitude is a function of the bending stiffness and natural frequencies of the corresponding plate. It is concluded in the present work that the Strouhal number of vortex shedding or the frequency of plate deflection is difficult to estimate using natural frequencies of the plate, which are calculated by inducing free vibration, since the fluid loading is distributed non-uniformly over the plate rather than concentrated at the tip of the plate. The present study suggests that the flexibility of a splitter plate, in general, adversely modulates the drag and lift forces acting on the cylinder surface while it promotes the oscillation of the plate.

Driving can occupy a considerable part of our daily lives and is often associated with high levels of stress. Motivated by the effectiveness of controlled breathing, this work studies the potential use of breathing interventions while driving to help manage stress. In particular, we implemented and evaluated a closed-loop system that monitored the breathing rate of drivers in real-time and delivered either a conscious or an unconscious personalized acoustic breathing guide whenever needed. In a study with 24 participants, we observed that conscious interventions more effectively reduced the breathing rate but also increased the number of driving mistakes. We observed that prior driving experience as well as personality are significantly associated with the effect of the interventions, which highlights the importance of considering user profiles for in-car stress management interventions. CCS CONCEPTS • Human-centered computing → Auditory feedback; Empirical studies in HCI ; • Applied computing → Consumer health.

Figure 1: (a) aSpire, a clippable pneumatic-tactile feedback device with 3 soft actuators. (b) Control UI that allows users to select/create diferent tactile patterns. (c) User test of aSpire on passengers in on-road commuting environment. aSpire clipped on; (d) a seat-belt for breathing guidance and providing comfort for vehicle passengers, (e) a back pack strap during walking.

No abstract

No abstract