bluuebunny/crossref_metadata_2025_split huggingface dataset:
System-Level Design Tools Utilizing OPM and Modelica
Authors: Sutherland Joshua , Oizumi Kazuya , Aoyama Kazuhiro , Eguchi Takao , Takahashi Naoki 
Published: December 2016

This paper presents a methodology and tools to synthesize and assess different System-Level Designs. It utilizes the descriptive modeling language Object Process Methodology (OPM) to hierarchically describe the functionality of the System of Interest which is mapped by way of various intermediary models to an architecture in the Modelica numerical modeling language. The resulting Modelica architecture model is subsequently used as a framework for the rapid creation of alternative System of Interest designs by the variation of components.
To enable consistent assessment of the alternatives, Assessment Scenarios are created based on the functionality identified by OPM decomposition. By defining a hierarchy of Modelica models with the Assessment Scenarios at the top, all the System of Interest alternative models can be composed into the Assessment Scenarios and the resulting models simulated. With a combined score for each alternative across all the Assessment Scenarios being computed by way of Multi Objective Decision Analysis (MODA).
This paper demonstrates the approach with an actual student solar powered autonomous boat development project.
ADAPt Design: A Methodology for Enabling Modular Design for Mission Specific SUAS
Authors: Fisher Zachary C. , Locascio David , Cooksey K. Daniel , Mavris Dimitri N. , Spero Eric 
Published: December 2016

Recent advances in small unmanned aircraft systems (SUAS) have greatly broadened the scope of their potential applications. However, traditional design processes applied to SUAS produce a single design for a single set of requirements. Off-design mission performance is often greatly degraded due to the vehicle’s small scale. This paper considers a different approach to SUAS design aimed at addressing this issue. In this approach, a hybrid modular and scalable product family is coupled with linked engineering analyses in order to automatically formulate a design given a set of mission requirements. This allows multiple SUAS designs to be rapidly synthesized from multiple sets of design requirements using a common set of components. Designs are then rapidly generated and manufactured “on-demand” using automated manufacturing techniques in order to address unforeseen mission needs.
The design approach, named “Aggregate Derivative Approach to Product Design” (ADAPt Design), consists of four actions: (1) requirements analysis, (2) architecture selection, (3) interface design, and (4) concept refinement and design. The outcomes of the method are a family of designs which are highly compatible with design automation, and a toolset that automatically translates changes in requirements to changes in detailed 3-D models. Results of the application of this approach are presented via the design of several SUAS. The capability of the design paradigm is assessed through a comparison of design requirements to the measured performance of the designed vehicle, and conclusions are drawn about the approach’s applicability and scalability.
Sensitivity of Final Field Position to the Punt Initial Conditions in American Football
Authors: Turner James D. , Mann Brian P. 
Published: December 2016

The starting field position is often a deciding factor in an American football game. In the case of a defensive stop, a kick, known as a punt, is used to give the receiving team a field position that is more advantageous to the kicking team when possession changes. The goal of the punter is to kick the ball along a desired flight path, where a delicate balance between the distance traveled before impact, hang time in the air, and the distance traveled after bouncing is favorable for the kicking team. However, the punter has only imprecise control over the initial conditions, such as the angular velocity, linear velocity, and orientation of the football. Due to the highly nonlinear behavior of the football, from aerodynamic and impact forces, even small changes in initial conditions can produce large changes in the final position of the football, but there may be regions of initial conditions with relatively consistent results. If punters could target such large contiguous regions of initial conditions with desirable football paths, they could improve their chances of successful kicks.
For nonlinear systems, basins of attraction diagrams are often used to graphically display the initial conditions that lead to different final attractors. In this case, the regions of initial conditions that lead to a desirable final field position can be grouped and shown graphically. A numerical simulation program was developed including models for aerodynamic flight and bouncing of the irregularly shaped football. The flight model used fourth order Runge-Kutta integration of the equations of motion of the football, including gravitational and aerodynamic forces and moments with empirical lift, drag, and yaw coefficients in three dimensions. The bounce model was based on an empirical two-dimensional coefficient of restitution model that was published in the literature. The behavior of a football in flight and during bouncing was simulated for a range of initial angular velocities and launch angles, and the characteristics of the flight paths were analyzed. The characteristics of some regions of initial conditions were relatively sensitive to small changes, while other regions were relatively uniform. This shows that this approach, with a quantitatively accurate bounce model, could be practically applied to develop a guide for punters to optimize their kicks. With such a guide and sufficient practice, punters could select and target the larger regions of initial conditions that produced desirable behavior, which would improve their chances of successful punts.
Investigating the Use of Smell in Vehicle-Driver Interaction
Authors: Bordegoni Monica , Carulli Marina , Shi Yuan 
Published: December 2016

Every year approximately more than one million people die on world’s road. Human factors are the largest contributing factors to the traffic crashes and fatality, and recent researches have identified drivers’ cognitive aspect as the major cause of human errors in 80% of crash events. Thus, the development of countermeasures to manage drivers’ cognitive aspect is an important challenge to address. Driver-Assistance Systems have been developed and integrated into vehicles to acquire data about the environment and the driver, and to communicate information to the driver, usually via the senses of vision and hearing. Unfortunately, these senses are already subjected to high demands, and the visual and auditory stimuli can be underestimate or considered as annoying. However, other sensory channels could be used to elicit the drivers’ cognitive aspect. In particular, smell can impact on various aspects of humans’ psychological state, such as people’s attention level, and can induce activation states in people.
The research presented in this paper aims at investigating whether olfactory stimuli, instead of auditory ones, can be used to influence the cognitive aspect of the drivers. For this purpose, an experimental framework has been set up and experimental testing sessions have been performed. The experimental framework is a multisensory environment consisting of an active stereo-projector and a screen used for displaying a video that reproduces a very monotonous car trip, a seating-buck for simulating the car environment, a wearable Olfactory Display, in-ear earphones and the BioGraph Infiniti system for acquiring the subjects’ physiological data.
The analysis of the data collected in the testing sessions shows that, in comparison to the relaxation state, olfactory stimuli are effective in increasing subjects’ attention level more than the auditory ones.
Curved Compliant Facet Origami-Based Self-Deployable Gliding Wing Module for Jump-Gliding
Authors: Baek Sang-Min , Lee Dae-Young , Cho Kyu-Jin 
Published: December 2016

In this paper, we propose a self-deployable origami structure and its application to a gliding wing module for jump-gliding. Generally, origami structures are composed of flat rigid facets. By using curved compliant facets instead of flat rigid facets, we endowed the origami structure with the ability to self-deploy and self-lock. When the origami structure is folded, the curved facets gradually flatten, and potential energy is stored on the flattened facets. By using the stored energy, the structure can rapidly deploy without an actuator. The geometry of the curved facet generates a notably high joint stiffness in the deployed state, which can be used as a self-locking mechanism.
In jump-gliding, the gliding wing should be foldable and lightweight for efficient jumping and capable of rapid deployment for efficient gliding. By applying the suggested origami structure as a basic frame, the deployable gliding wing module can satisfy these requirements. The wing span of the module is 44.7 cm, and it weighs 20.3 g including a battery and a servo motor. The module can be folded in 1/8.1 of the deployed area, and it deploys within 350 ms when it needs to glide.
Numerical Simulation of Flow Induced by Multiple DBD Plasma Actuators
Authors: Shan Hua , Aram Shawn , Lee Yu-Tai 
Published: December 2016

Active flow separation control using dielectric barrier discharge (DBD) plasma actuators oriented in the spanwise direction has been successfully investigated by the authors using an integrated numerical simulation tool that couples the unsteady Reynolds averaged Navier-Stokes (URANS) or large eddy simulation (LES) solver for incompressible flows with the DBD electro-hydrodynamic (EHD) body force model. Although many experimental and numerical investigations have indicated that the spanwise-oriented DBD plasma actuator is an effective flow control method, the application is difficult to extend from model-scale to full-scale problems, partly due to the required high amplitude and high bandwidth excitation. Also, the flow control mechanism associated with a spanwise-oriented DBD actuator is mainly direct momentum injection, therefore, the effectiveness of actuation is sensitive to the location of the DBD actuator relative to the location of flow separation. On the other hand, a few experimental studies have shown promising results using the DBD Vortex Generator (DBD-VG) consisting of multiple plasma DBD actuators oriented in the streamwise direction. By generating streamwise vortices extending a long distance downstream, the DBD-VGs enhance the mixing of the inner and outer layers of turbulent boundary layer flows. As a result, the boundary layer can better withstand an adverse pressure gradient. When applied to flow separation control, the effectiveness of the DBD-VGs should be less sensitive to location of flow separation.
The present work extends the capability of the integrated numerical simulation tool from a single spanwise-oriented DBD plasma actuator to multiple DBD plasma actuators oriented in any direction, including the streamwise direction. As a demonstration of the new capability in the DBD-URANS coupled solver, numerical simulations of flow induced by a DBD-VG actuator with an array of exposed electrodes in a quiescent environment, as well as in a turbulent boundary layer over a flat plate, are carried out. The numerical simulation successfully reproduced the longitudinal vortices embedded in the boundary layer.
Improvement of Outlet Nozzle Shape for Pressure-Loss Reduction in Air Conditioner
Authors: Sato Daiwa , Iwase Taku , Obara Hideshi , Fushimi Naoyuki 
Published: December 2016

A reduction of fan power is required to develop high efficiency air conditioner. Fan-power reduction is achieved by reducing of the pressure loss of flow channels and/or improving the efficiency of a fan. An indoor unit of the air conditioner in the present study is installed on a ceiling in a room. The indoor unit consists of a centrifugal fan, a heat exchanger, an air inlet and 4 air-outlet nozzles. One of the areas of the highest pressure-loss in the indoor unit is around the air-outlet nozzles since the cross-section of the flow channel in the air-outlet nozzles is smaller than those in other areas. In addition, the path of air flow after passing through the heat exchanger is sharply turned downward by a cabinet wall of the indoor unit. The air flow separates in the air-outlet nozzles when the air flow gets over a drain pan which receives water condensed on the surface of the heat exchanger. As a result, the effective cross-section of the air-outlet nozzles is further reduced due to the flow separation. This is main cause of the pressure-loss in the air-outlet nozzles.
The optimum nozzle shape to suppress flow separation in air-outlet nozzles of the indoor unit of an air conditioner was determined. An edge, shaped on the wall of the drain pan, minimized the flow separation by corresponding to the location between the edge and the attachment point of the flow separation. The location of the edge is defined by two parameters, and the influence of the parameters on reduction of fan power was determined by using Computational Fluid Dynamics (CFD). A CFD model of a whole indoor unit (including fan, heat exchanger, air-outlet nozzles) was applied to accurately predict fan power for different locations of the edge. Furthermore, the flow separation in the air-outlet nozzle was visualized on the basis of the CFD results. To obtain the appropriate combination of parameters to suppress the flow separation, a response surface based on the CFD results and approximate values given by a Kriging-based method, was used. The Kriging-based model is one of the response-surface methods and is characterized by approximating a nonlinear function based on Bayesian probabilistic estimation. The response surface provided the area containing the appropriate parameters for reducing fan power (“parameter area”, hereafter). The parameter area of fan-power reduction on the response surface was found. The CFD results confirm that the flow separation corresponds to the edge location given by this parameter area and that the edge minimizes the flow separation. To experimentally verify the effect of the edge on fan-power reduction, four points in the parameter area for fan-power reduction were selected, and four nozzle shapes with these parameters were prototyped. It was found that fan power was reduced (at most) by 9.9% by the optimized nozzles shapes in comparison with the current shape of air-outlet nozzles.
Influence of Inclination Angle on Intermittent Two Phase Flows
Authors: Escrig Escrig Josep , Hewakandamby Buddhika , Dimitrakis Georgios , Azzopardi Barry 
Published: December 2016

Intermittent gas and liquid two-phase flow was generated in a 6 m × 67 mm diameter pipe mounted rotatable frame (vertical up to −20°). Air and a 5 mPa s silicone oil at atmospheric pressure were studied. Gas superficial velocities between 0.17 and 2.9 m/s and liquid superficial velocities between 0.023 and 0.47 m/s were employed. These runs were repeated at 7 angles making a total of 420 runs.
Cross sectional void fraction time series were measured over 60 seconds for each run using a Wire Mesh Sensor and a twin plane Electrical Capacitance Tomography. The void fraction time series data were analysed in order to extract average void fraction, structure velocities and structure frequencies.
Results are presented to illustrate the effect of the angle as well as the phase superficial velocities affect the intermittent flows behaviour. Existing correlations suggested to predict average void fraction and gas structures velocity and frequency in slug flow have been compared with new experimental results for any intermittent flow including: slug, cap bubble and churn. Good agreements have been seen for the gas structure velocity and mean void fraction. On the other hand, no correlation was found to predict the gas structure frequency, especially in vertical and inclined pipes.
Parametric Study of Erosion Under High Concentrated Slurry: Experimental and Numerical Analyses
Authors: Mahdavi Marzieh , Karimi Soroor , Shirazi Siamack A. , McLaury Brenton S. 
Published: December 2016

Highly concentrated slurries are found in many different industrial and environmental applications, such as hydro-transport systems of the oil sands industry, drilling and fracturing applications, and stirring vessels. When the volume fraction of particles is low, particles have little influence on the structure of the flow. However, even when average concentration is relatively low, there can still be some regions of high concentration. In highly concentrated flows, the effect of particles on the dynamics of the flow cannot be neglected. Under this condition, particle concentration can affect the turbulence intensity and erosion ratio.
Several experiments have been conducted to examine the effect of different parameters on erosion. Different models have been developed to predict erosion ratio in liquid and gas flows. However, previous studies mostly have examined dilute slurries and less attention has been paid to the effect of high concentration of particles on erosion. In this study, the erosion due to highly concentrated slurries is investigated using both experimental and numerical approaches. There are several parameters such as particle properties and shape, target material, fluid properties and dynamics of the flow that affect erosion ratio. In addition, higher fluid viscosity can significantly affect the flow dynamics and change the interaction behavior between fluid and solid particles.
Effects of particle size and velocity on erosion ratio are investigated for different sand concentrations. Experiments have been conducted for various concentrations, ranging from 1% to about 20% by mass and two different particle sizes, 75 μm and 300 μm. Erosion ratio was calculated based on two different approaches, mass loss and volume loss obtained from 3-D profilometry data. Scanning electron microscope (SEM) images were obtained for 1% and 15% concentration cases to examine the erosion on different parts of the specimens. In addition to the experimental work, a CFD model is setup to simulate the erosion results. The aim of this CFD simulation is to predict erosion rate of the specimen caused by submerged slurry jet flow by using Reynolds stress as turbulence model. The fluid flow solution is obtained using an Eulerian approach and a Lagrangian scheme is used to track the sand particles. In these models, the injected particles from the inlet impact the target wall in order to investigate the erosion.
Wingtip Devices for Tidal Turbines: Performance Improvement and Cavitation Mitigation
Authors: Nedyalkov Ivaylo , Gagnon Ian , Shull Jesse , Brindley John , Wosnik Martin 
Published: December 2016

Wingtip devices are common in aeronautical applications and are increasingly used on wind turbines. However, their use in hydrokinetic energy conversion applications such as tidal turbines to date is minimal, due to the concern for increased bio-fouling and also the fact that there is little or no data publically available describing their cavitation characteristics. In this study, three wingtip designs were considered for hydrokinetic turbine applications: a plain foil with a rounded tip (considered the reference case), a generic wingtip device (a winglet), and a novel “split-tip” device. The tips were studied numerically and experimentally at different angles of attack. The numerical simulations were performed in OpenFOAM using the k-omega SST model to predict the lift and drag characteristics of a “base” foil with each of the three wingtip devices. Additionally the pressure and vorticity were observed. Experiments were conducted in the University of New Hampshire High-Speed Cavitation Tunnel – HiCaT. A modular experimental test bed with an elliptical foil section was developed specifically for the study. The test bed extends to the centerline of the tunnel where wingtips are attached, and has four small-diameter tube openings to accommodate pressure measurements and/or mass injection studies. Water tunnel data were obtained for lift, and cavitation inception, and compared to the numerical simulations. The numerical results show decreased vorticity with presence of the wingtip devices, however, the advantage of using wingtips for decreasing drag and increasing lift forces is not conclusively exhibited. The experimental measurements suggest that there is a significant suppression of tip vortex cavitation with the use of wingtip devices at high angles of attack (around 10 degrees), but the advantage of using the wingtip devices diminishes at lower angles of attack.
It was shown by Arndt [1] that tip-vortex cavitation on hydrofoils can be related to the lift coefficient and the Reynolds number, where the cavitation index at inception is proportional to the square of the section lift coefficient and the Reynolds number based on hydrofoil chord, taken to the power m. The power exponent m has been generally accepted to be approximately 0.4. This relation is made into an equation via a coefficient of proportionality K, which depends on the wingtip and foil section geometry, and has been empirically determined to have values between 0.025 and 0.056 for previously investigated wings. While the value of the coefficient K for the reference wing tip remained comparatively constant for the range of conditions investigated (angles of attack, Reynolds numbers), it varied significantly for the foil terminated by the winglet. This may be due to the non-elliptical load distribution in the span-wise direction, but also raises the question whether the standard tip-vortex cavitation correlation for hydrofoils is applicable for general wingtip devices.