Experimental Analysis of the Impact of Injected Biofuels on In-Cylinder Flow Structures

For many application areas such as autonomous navigation, the ability to accurately perceive the environment is essential. For this purpose, a wide variety of well-researched sensor systems are available that can be used to detect obstacles or navigation targets. Stereo cameras have emerged as a very versatile sensing technology in this regard due to their low hardware cost and high fidelity. Consequently, much work has been done to integrate them into mobile robots. However, the existing literature focuses on presenting the concepts and algorithms used to implement the desired robot functions on top of a given camera setup. As a result, the rationale and impact of choosing this camera setup are usually neither discussed nor described. Thus, when designing the stereo camera system for a mobile robot, there is not much general guidance beyond isolated setups that worked for a specific robot. To close the gap, this paper studies the impact of the physical setup of a stereo camera system in indoor environments. To do this, we present the results of an experimental analysis in which we use a given software setup to estimate the distance to an object while systematically changing the camera setup. Thereby, we vary the three main parameters of the physical camera setup, namely the angle and distance between the cameras as well as the field of view and a rather soft parameter, the resolution. Based on the results, we derive several guidelines on how to choose the parameters for an application.

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An experimental study of underexpanded sonic, coaxial, swirl jets

Proceedings of the Institution of Mechanical Engineers Part C Journal of Mechanical Engineering Science ◽

10.1243/095440604322786974 ◽

2004 ◽

Vol 218 (1) ◽

pp. 93-103 ◽

Cited By ~ 4

Author(s):

K-H Lee ◽

T Setoguchi ◽

S Matsuo ◽

H-D Kim

Keyword(s):

Static Pressure ◽

Near Field ◽

Flow Structures ◽

Experimental Investigations ◽

Pressure Measurements ◽

Annular Nozzle ◽

Free Jets ◽

Underexpanded Jets ◽

Secondary Stream ◽

The Impact

The present study addresses experimental investigations of the near-field flow structures of an underexpanded sonic, dual, coaxial, swirl jet. The swirl stream is discharged from the secondary annular nozzle and the primary inner nozzle provides the underexpanded free jets. The interactions between the secondary swirl and primary underexpanded jets are quantified by a fine pitot impact and static pressure measurements and are visualized using a shadowgraph optical method. The pressure ratios of the secondary swirl and primary underexpanded jets are varied below 7.0. Experiments are conducted to investigate the effects of the secondary swirl stream on the primary underexpanded jets, compared with the secondary stream of no swirl. The results show that the presence of an annular swirl stream causes the Mach disc to move further downstream, with an increased diameter, and remarkably reduces the fluctuations of the impact pressures in the underexpanded sonic dual coaxial jet, compared with the case of the secondary annular stream with no swirl.

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Experimental Study of Large-Scale Flow Structures in an Aneurysm

Volume 1: Flow Manipulation and Active Control; Bio-Inspired Fluid Mechanics; Boundary Layer and High-Speed Flows; Fluids Engineering Education; Transport Phenomena in Energy Conversion and Mixing; Turbulent Flows; Vortex Dynamics; DNS/LES and Hybrid RANS/LES Methods; Fluid Structure Interaction; Fluid Dynamics of Wind Energy; Bubble, Droplet, and Aerosol Dynamics ◽

10.1115/fedsm2018-83531 ◽

2018 ◽

Author(s):

Paulo Yu ◽

Vibhav Durgesh

Keyword(s):

Large Scale ◽

Flow Structures ◽

Pump System ◽

Vortical Structures ◽

Abnormal Growth ◽

Image Velocimetry ◽

Large Scale Flow ◽

The Impact ◽

Inflow Conditions ◽

Aneurysm Model

An aneurysm is an abnormal growth in the wall of a weakened blood vessel, and can often be fatal upon rupture. Studies have shown that aneurysm shape and hemodynamics, in conjunction with other parameters, play an important role in growth and rupture. The objective of this study was to investigate the impact of varying inflow conditions on flow structures in an aneurysm. An idealized rigid sidewall aneurysm model was prepared and the Womersley number (α) and Reynolds number (Re) values were varied from 2 to 5 and 50 to 250, respectively. A ViVitro Labs pump system was used for inflow control and Particle Image Velocimetry was used for conducting velocity measurements. The results showed that the primary vortex path varied with an increase in α, while an increase in Re was correlated to the vortex strength and formation of secondary vortical structures. The evolution and decay of vortical structures were also observed to be dependent on α and Re.

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The Application of CFD Methods to Analyse the Flow Structures in the Radial Labyrinth Pump

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.630.52 ◽

2014 ◽

Vol 630 ◽

pp. 52-60 ◽

Cited By ~ 1

Author(s):

Przemyslaw Szulc

Keyword(s):

Energy Conversion ◽

Numerical Simulations ◽

Structural Changes ◽

Flow Structures ◽

Pump Performance ◽

The Impact ◽

Made In

The radial labyrinth pump consists of two discs: passive and active. Both discs are equipped in special blades with the opposite angle of milling. The passive disc is motionless and the active one rotates around the axis of the pump. On the surface of the connection of two blades belonging to different discs the circulation of fluid, as a type of energy conversion is expected. To investigate the analysed set of discs and take into consideration the impact of some structural changes of the geometry of both discs on a pump performance the numerical simulations were made. In this paper the results of CFD research of the flow in the radial labyrinth pump are presented.

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Turbulent Kinetic Energy in Bolt Fishway

AgriEngineering ◽

10.3390/agriengineering1020020 ◽

2019 ◽

Vol 1 (2) ◽

pp. 265-282

Author(s):

Marta Puzdrowska ◽

Tomasz Heese

Keyword(s):

Spatial Distribution ◽

Kinetic Energy ◽

Turbulent Kinetic Energy ◽

Laboratory Tests ◽

Flow Structures ◽

3D Flow ◽

Velocity Magnitude ◽

Biological Development ◽

The Impact ◽

Channel Development

The paper presents an analysis the spatial distribution of turbulent kinetic energy (TKE) for bolt fishways, including the impact of additional spillway slots and fixed channel development. The research was done for two models, each containing a different arrangement of slots. The presented results of research for bolt fishways were obtained as an effect of laboratory tests. The measurements were done for three components of instant flow velocity magnitude (speed). Analysis of the results was done for a 3D flow structure using Matlab software. In the case of bolt fishways, significant differences were noted for the method of velocity and TKE distribution, in reference to research comprising channels with biological development. It was stated that a reason for this is the flexible development of the channel. The occurrence of extreme TKE values in the chamber (pool) is strictly associated with the characteristics of interaction zones between various flow structures. It was also stated that the lower the parapet of the slot’s spillway shelf is in the fishway’s partition, the higher TKE could be expected just downstream of the section. These establishments may be important for the designing process in the case of fish passes of various types of construction.

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