Olfactory Display Using Solenoid Valves and Fluid Dynamics Simulation

2012 ◽  
pp. 140-163 ◽  
Author(s):  
Takamichi Nakamoto ◽  
Hiroshi Ishida ◽  
Haruka Matsukura
Keyword(s):  
Fluid Dynamics ◽  
High Speed ◽  
Cfd Simulation ◽  
Solenoid Valve ◽  
Odor Intensity ◽  
Dynamics Simulation ◽  
Odor Source ◽  
The Real ◽  
High Speed Switching ◽  
Olfactory Display

Olfaction is now becoming available in Multiple Sensorial Media because of recent progress of an olfactory display. One of the important functions of the olfactory display is to blend multiple of odor components to create a variety of odors. We have developed the olfactory display to blend up to 32 odor components using solenoid valves. High -speed switching of a solenoid valve enables us to blend many odors instantaneously at any recipe even if the solenoid valve has only two states such as ON and OFF. Since it is compact and is easy to use, it has been so far used to demonstrate a movie, an animation and a game with scents. However, a contents developer must manually adjust its concentration sequence because the concentration varies from place to place. The manually determined concentration sequence is not accurate and, moreover, it takes much time to make the plausible concentration sequence manually. Thus, it is adequate to calculate the concentration sequence using CFD (Computational Fluid Dynamics) simulation in the virtual environment. Since the spread of odor in spatial domain is very complicated, the isotropic diffusion from the odor source is not valid. Since the simulated odor distribution resembles the distribution actually measured in the real room, CFD simulation enables us to reproduce the spatial variation in the odor intensity that the user would experience in the real world. Most of the users successfully perceived the intended change in the odor intensity when they watched the scented movie, in which they approached an odor source hindered by an obstacle. Presentation of the spatial odor distribution to the users was tried, and encouraging results were obtained.

Application of Computational Fluid Dynamics Simulation to Squeeze Film Damper Analysis

2017 ◽  
Vol 139 (10) ◽  
Author(s):  
Gil Jun Lee ◽  
Jay Kim ◽  
Tod Steen
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
High Speed ◽  
Cfd Simulation ◽  
Design Guidelines ◽  
Dynamics Simulation ◽  
Squeeze Film ◽  
Computational Time ◽  
Small Clearance ◽  
Computational Fluid Dynamics Cfd

Squeeze film dampers (SFDs) are used in high-speed turbomachinery to provide external damping to the system. Computational fluid dynamics (CFD) simulation is a highly effective tool to predict the performance of SFDs and obtain design guidance. It is shown that a moving reference frame (MRF) can be adopted for CFD simulation, which saves computational time significantly. MRF-based CFD analysis is validated, then utilized to design oil plenums of SFDs. Effects of the piston ring clearances, the oil groove, and oil supply ports are studied based on CFD and theoretical solutions. It is shown that oil plenum geometries can significantly affect the performance of the SFD especially when the SFD has a small clearance. The equivalent clearance is proposed as a new concept that enables quick estimation of the effect of oil plenum geometries on the SFD performance. Some design practices that have been adopted in industry are revisited to check their validity. Based on simulation results, a set of general design guidelines is proposed.

scholarly journals High-speed prediction of computational fluid dynamics simulation in crystal growth

CrystEngComm ◽  
2018 ◽  
Vol 20 (41) ◽  
pp. 6546-6550 ◽  
Author(s):  
Yosuke Tsunooka ◽  
Nobuhiko Kokubo ◽  
Goki Hatasa ◽  
Shunta Harada ◽  
Miho Tagawa ◽  
...  
Keyword(s):  
Machine Learning ◽  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
High Speed ◽  
Cfd Simulation ◽  
Large Diameter ◽  
Dynamics Simulation ◽  
Computational Fluid Dynamics Simulation ◽  
High Quality ◽  
Speed Prediction

The combination of the CFD simulation and machine learning thus makes it possible to determine optimized parameters for high-quality and large-diameter crystals.

Flow conditions in the grooves of a Low-Consistency refiner

2012 ◽  
Vol 27 (2) ◽  
pp. 173-183 ◽  
Author(s):  
Lisa Prahl Wittberg ◽  
Magnus Björkman ◽  
Gohar Khokhar ◽  
Ulla-Britt Mohlin ◽  
Anders Dahlkild
Keyword(s):  
Fluid Dynamics ◽  
Flow Pattern ◽  
High Speed ◽  
Cfd Simulation ◽  
Flow Conditions ◽  
Shear Forces ◽  
High Speed Imaging ◽  
Newtonian Flows ◽  
Computational Fluid Dynamics Cfd ◽  
Vortical Motion

Abstract The flow pattern in the grooves plays a major role for the homogeneity of refining as well as for the transfer and loading of fiber flocs in refining position on the bar edges. However, it is an area where very little information is available. In the present study, flow conditions in the grooves in a Low-Consistency (LC) - disc refiner were studied both experimentally and numerically. The experimental study involved high-speed imaging through a 3 cm peephole into a commercial refiner. The Computational Fluid Dynamics (CFD) simulation focused on the flow condition in a radial groove, considering both Newtonian and non-Newtonian flows. Flow conditions for stator and rotor grooves were modeled along the groove at different angular speeds and pressure differences over the refiner. Both the experimental and the modeling results show a dual flow pattern in the grooves; a rotational/spiral movement at the top of the groove and a flow in the direction of the groove at the bottom, which to the authors knowledge has not been reported in literature. The strong vortical motion at the top of the grooves observed both for the rotor and the stator are believed to be important for placing the fibers onto the bar edges and to induce shear forces in such a way that the fibers get treated. Moreover, a large sensitivity to suspension properties in terms of the development of flow pattern was detected.

Particle Image Velocimetry Experiment and Computational Fluid Dynamics Simulation of Flow Around Rigid Cylinder

2018 ◽  
Vol 140 (5) ◽  
Author(s):  
Guangyao Wang ◽  
Ye Tian ◽  
Spyros A. Kinnas
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Particle Image Velocimetry ◽  
Vector Fields ◽  
Particle Image ◽  
Cfd Simulation ◽  
Dynamics Simulation ◽  
Reynolds Stresses ◽  
Rigid Cylinder ◽  
Image Velocimetry

This work focuses on the study of the flow around a rigid cylinder with both particle image velocimetry (PIV) experiment and computational fluid dynamics (CFD) simulation. PIV measurements of the flow field downstream of the cylinder are first presented. The boundary conditions for CFD simulations are measured in the PIV experiment. Then the PIV flow is compared with both Reynolds-averaged Navier–Stokes (RANS) two-dimensional (2D) and large eddy simulation (LES) three-dimensional (3D) simulations performed with ANSYS fluent. The velocity vector fields and time histories of velocity are analyzed. In addition, the time-averaged velocity profiles and Reynolds stresses are analyzed. It is found that, in general, LES (3D) gives a better prediction of flow characteristics than RANS (2D).

Incorporating Fluid Dynamics Considerations into Olfactory Displays

2012 ◽  
pp. 415-428 ◽  
Author(s):  
Haruka Matsukura ◽  
Hiroshi Ishida
Keyword(s):  
Fluid Dynamics ◽  
Cfd Simulation ◽  
Indoor Environments ◽  
Odor Concentration ◽  
Turbulent Airflow ◽  
Airflow Field ◽  
Computational Fluid Dynamics Cfd ◽  
Sensory Tests ◽  
Body Heat ◽  
Olfactory Display

In this chapter, the authors describe fluid dynamics considerations regarding odor dispersal in real environments and their relationship with realistic odor presentation using an olfactory display. The authors propose the use of a Computational Fluid Dynamics (CFD) simulation in conjunction with the olfactory display. A CFD solver is employed to calculate the turbulent airflow field in a given environment and the dispersal of odor molecules from their source. The simulation result is used to reproduce realistic changes in the odor concentration with time and space at the nose. The results of sensory tests are presented as a demonstration of CFD-based odor presentation. The effect of body heat on odor dispersal in indoor environments and how it affects odor perception is also discussed.

Fluid Dynamic Considerations for Realistic Odor Presentation Using Olfactory Display

2010 ◽  
Vol 19 (6) ◽  
pp. 513-526 ◽  
Author(s):  
Haruka Matsukura
Keyword(s):  
Molecular Diffusion ◽  
Cfd Simulation ◽  
Fluid Dynamic ◽  
Real Life ◽  
Odor Intensity ◽  
Odor Concentration ◽  
Sensory Test ◽  
Olfactory Sensation ◽  
Olfactory Adaptation ◽  
Olfactory Display

This paper describes some fluid dynamic considerations for attaining realistic odor presentation using an olfactory display. Molecular diffusion is an extremely slow process and odor molecules released from their source are spread by being carried off by airflow. Therefore, we propose to use a computational fluid dynamics (CFD) simulation in conjunction with the olfactory display. The CFD solver is employed to calculate the turbulent airflow field in the given environment and the dispersal of odor molecules from their source. The simulation result is used to reproduce at the nose the realistic change in the odor concentration with time and space. However, our initial sensory test for evaluating the proposed method was not completely successful, and we also found some discrepancies between our real-life olfactory sensation and the experience of the CFD-based olfactory display. Here we report some insights to overcome these problems. In the initial sensory test, a nontrivial portion of the subjects did not properly recognize the spatial variation in the odor intensity. The result of our recent sensory test is presented in this paper to show that better contrast in the perceived odor intensity can be provided when the concentration range of the released odor is adjusted for the variation in the olfactory sensitivity of individual subjects. We noted that olfactory adaptation occurred more quickly in the initial sensory test of the CFD-based olfactory display than in real environments. In this paper, we show that olfactory adaptation can be alleviated by modulating the odor concentration randomly to mimic the random fluctuations of the turbulent flow fields in real environments. We also noted in our initial sensory test that there were sometimes discrepancies between our olfactory sensation in real environments and the simulated odor distribution. We show in this paper that the discrepancy can be attributed to the convection caused by the human body temperature that brings an odor vapor that is drifting around our feet up to our noses.

Computational Fluid Dynamics Simulation of the Right Coronary Artery Moving With the Cardiac Wall

2002 ◽  
Author(s):  
H. Hayashi ◽  
T. Yamaguchi
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Coronary Artery ◽  
Right Coronary Artery ◽  
Cfd Simulation ◽  
Dynamics Simulation ◽  
Cardiac Wall ◽  
Computational Fluid Dynamics Cfd ◽  
The Right ◽  
Heart Wall

The beating motion of the heart wall, to which the major coronary arteries are fixed, is interesting, due to its possible mechanical influence on the flow inside the artery, and hence its effect on atherogenesis [1–2]. In this study, we conducted a computational fluid dynamics (CFD) simulation using a simplified model of the right coronary artery, which deforms with heart contractions. The results are discussed with respect to the local hemodynamics characteristics, particularly the streamline pattern and the wall shear stress distribution.

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