Danyang Fan

3D-printing can benefit blind and low-vision (BLV) users by offering tactile access to information typically conveyed visually. Complex printed models often require users to assemble multiple components, a process that relies on visual cues for sighted individuals, while the assembly experiences of BLV users remain poorly understood. In this work, we investigate how BLV users experience and navigate 3D-printed object assembly. We conducted a user study with six BLV participants under three conditions: (1) unassisted, (2) assisted by a sighted mediator, and (3) guided by step-by-step verbal instructions. Verbal instructions helped participants identify, confirm, orient, and fasten components; but challenges locating and distinguishing joints persisted. Co-designing with BLV users identified uses for tactile markers to complement verbal cues and support spatially relevant aspects of the assembly process. Our results highlight the need for assembly instructions tailored to BLV users, and we conclude with recommendations for future research and development.

Interactive data learning tools provide explorable ways for students to build intuitions about data, data representations, and statistical parameters. However, these tools rely on visual consumption and are not accessible to blind and low vision (BLV) students. In this work, we investigate opportunities to leverage active exploration, enriched with multimodal feedback and embodied interaction, to foster an understanding of the relationships among individual data values, data representations, and statistical measures. We explore these opportunities in the form of an accessible learning platform that allows students to hear and feel how statistical measures are changing in real time as they construct and manipulate physicalized data representations. We introduced the platform to four teachers of students with visual impairments (TVIs) through a two-hour-long focus group. TVIs embraced the platform's exploratory nature and universality and recommended the consideration of additional auditory and texture-based interactions to enhance engagement.

Data visualization has become an increasingly important means of effective data communication and has played a vital role in broadcasting the progression of COVID-19. Accessible data representations, however, have lagged behind, leaving areas of information out of reach for many blind and visually impaired (BVI) users. In this work, we sought to understand (1) the accessibility of current implementations of visualizations on the web; (2) BVI users’ preferences and current experiences when accessing data-driven media; (3) how accessible data representations on the web address these users’ access needs and help them navigate, interpret, and gain insights from the data; and (4) the practical challenges that limit BVI users’ access and use of data representations. To answer these questions, we conducted a mixed-methods study consisting of an accessibility audit of 87 data visualizations on the web to identify accessibility issues, an online survey of 127 screen reader users to understand lived experiences and preferences, and a remote contextual inquiry with 12 of the survey respondents to observe how they navigate, interpret, and gain insights from accessible data representations. Our observations during this critical period of time provide an understanding of the widespread accessibility issues encountered across online data visualizations, the impact that data accessibility inequities have on the BVI community, the ways screen reader users sought access to data-driven information and made use of online visualizations to form insights, and the pressing need to make larger strides towards improving data literacy, building confidence, and enriching methods of access. Based on our findings, we provide recommendations for researchers and practitioners to broaden data accessibility on the web.

Discrete hole film cooling is widely employed to protect turbine blades and vanes from hot combustion gases entering the high-pressure turbine stage. Accurate prediction of the heat transfer near film cooling holes is critical, and high-fidelity experimental data sets are needed for validation of new computational models. Relatively few studies have examined the effects of periodic main flow unsteadiness resulting from the interaction of turbine blades and vanes, with a particular lack of data for shaped hole configurations. Periodic unsteadiness was generated in the main flow over a laidback, fan-shaped cooling hole at a Strouhal number (St = fD/U) of 0.014 by an airfoil oscillating in pitch. Magnetic resonance imaging (MRI) with water as the working fluid was used to obtain full-field, phase-resolved velocity and scalar concentration data. Operating conditions consisted of a hole Reynolds number of 2900, channel Reynolds number of 25, 000, and blowing ratio of unity. Both mean and phase-resolved data are compared to the previous measurements for the same hole geometry with steady main flow. Under unsteady freestream conditions, the flow separation pattern inside the hole was observed to change from an asymmetric separation bubble to two symmetric bubbles. The periodic unsteadiness was characterized by alternating periods of slow main flow, which allowed the coolant to penetrate into the freestream along the centerplane, and fast, hole-impinging main flow, which deflected coolant toward the laidback wall and caused ejection of coolant from the hole away from the centerplane. Mean adiabatic surface effectiveness was reduced up to 23% inside the hole, while mean laterally averaged effectiveness outside the hole fell 28–36% over the entire measurement domain. A brief comparison to a round jet with and without unsteadiness is included; for the round jet, no disturbance was observed inside the hole, and some fluctuations directed coolant toward the wall, which increased mean film cooling effectiveness. The combined velocity and concentration data for both cases are suitable for quantitative validation of computational fluid dynamics predictions for film cooling flows with periodic freestream unsteadiness.