scholarly journals Marangoni effect inspired robotic self-propulsion over a water surface using a flow-imbibition-powered microfluidic pump

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Bokeon Kwak ◽  
Soyoung Choi ◽  
Jiyeon Maeng ◽  
Joonbum Bae
Keyword(s):  
Aquatic Insects ◽  
Water Surface ◽  
Liquid Fuel ◽  
Operation Time ◽  
Marangoni Effect ◽  
Design Parameters ◽  
Propulsion Systems ◽  
Time And Motion ◽  
Locomotory Behavior ◽  
Motion Directionality

AbstractCertain aquatic insects rapidly traverse water by secreting surfactants that exploit the Marangoni effect, inspiring the development of many self-propulsion systems. In this research, to demonstrate a new way of delivering liquid fuel to a water surface for Marangoni propulsion, a microfluidic pump driven by the flow-imbibition by a porous medium was integrated to create a novel self-propelling robot. After triggered by a small magnet, the liquid fuel stored in a microchannel is autonomously transported to an outlet in a mechanically tunable manner. We also comprehensively analyzed the effects of various design parameters on the robot’s locomotory behavior. It was shown that the traveled distance, energy density of fuel, operation time, and motion directionality were tunable by adjusting porous media, nozzle diameter, keel-extrusion, and the distance between the nozzle and water surface. The utilization of a microfluidic device in bioinspired robot is expected to bring out new possibilities in future development of self-propulsion system.

scholarly journals Multi-Objective Optimisation of Tyre and Suspension Parameters during Cornering for Different Road Roughness Profiles

2021 ◽  
Vol 11 (13) ◽  
pp. 5934
Author(s):  
Georgios Papaioannou ◽  
Jenny Jerrelind ◽  
Lars Drugge
Keyword(s):  
Optimal Solution ◽  
Design Parameters ◽  
Road Vehicles ◽  
Propulsion Systems ◽  
Vehicle Handling ◽  
Optimum Parameters ◽  
Trade Offs ◽  
Road Roughness ◽  
Control Technologies ◽  
Tyre Wear

Effective emission control technologies and novel propulsion systems have been developed for road vehicles, decreasing exhaust particle emissions. However, work has to be done on non-exhaust traffic related sources such as tyre–road interaction and tyre wear. Given that both are inevitable in road vehicles, efforts for assessing and minimising tyre wear should be considered. The amount of tyre wear is because of internal (tyre structure, manufacturing, etc.) and external (suspension configuration, speed, road surface, etc.) factors. In this work, the emphasis is on the optimisation of such parameters for minimising tyre wear, but also enhancing occupant’s comfort and improving vehicle handling. In addition to the search for the optimum parameters, the optimisation is also used as a tool to identify and highlight potential trade-offs between the objectives and the various design parameters. Hence, initially, the tyre design (based on some chosen tyre parameters) is optimised with regards to the above-mentioned objectives, for a vehicle while cornering over both Class A and B road roughness profiles. Afterwards, an optimal solution is sought between the Pareto alternatives provided by the two road cases, in order for the tyre wear levels to be less affected under different road profiles. Therefore, it is required that the tyre parameters are as close possible and that they provide similar tyre wear in both road cases. Then, the identified tyre design is adopted and the optimum suspension design is sought for the two road cases for both passive and semi-active suspension types. From the results, significant conclusions regarding how tyre wear behaves with regards to passenger comfort and vehicle handling are extracted, while the results illustrate where the optimum suspension and tyre parameters have converged trying to compromise among the above objectives under different road types and how suspension types, passive and semi-active, could compromise among all of them more optimally.

Theoretical Investigation of a Peristaltic Magneto-Fluid Dynamic Induction Compressor-2

1965 ◽  
Vol 9 (02) ◽  
pp. 56-65
Author(s):  
Joseph L. Neuringer ◽  
Eugene Migotsky ◽  
James H. Turner ◽  
Robert M. Haag
Keyword(s):  
Scaling Laws ◽  
Electromechanical Coupling ◽  
Constant Pressure ◽  
Fluid Dynamic ◽  
Pressure Rise ◽  
Magnetic Reynolds Number ◽  
Design Parameters ◽  
Propulsion Systems ◽  
Geometric Scaling ◽  
Axial Mass

In Part 3, the nature of the electromechanically induced motions inside the compressor both of the fluid conductor and of the pumped fluid when the electromechanical coupling is weak, i.e., in the limit of small magnetic Reynolds number, is investigated. The analysis predicts the development of a constant pressure gradient in the pumped fluid when the condition is imposed that the time-average axial mass flow across the conducting fluid annulus is zero. In Part 4, a preliminary feasibility study is made to determine whether the induction compressor has the potential to provide the pressure rise required to propel large and small undersea craft by means of jet propulsion systems for reasonable power and current-sheet inputs. Also determined here are the geometric scaling laws for the appropriate operating and design parameters.

scholarly journals Calculation of flow characteristics of liquid fuel supplied through pressure jet atomizers of small-sized gas turbine engines

2021 ◽  
Vol 20 (2) ◽  
pp. 19-35
Author(s):  
N. I. Gurakov ◽  
I. A. Zubrilin ◽  
M. Hernandez Morales ◽  
D. V. Yakushkin ◽  
A. A. Didenko ◽  
...  
Keyword(s):  
Gas Turbine ◽  
Liquid Fuel ◽  
Cone Angle ◽  
Flow Characteristics ◽  
Design Parameters ◽  
Turbine Engines ◽  
Gas Turbine Engines ◽  
Spray Cone Angle ◽  
Spray Cone ◽  
Semi Empirical

The paper presents the results of studying the flow characteristics of liquid fuel in pressure jet atomizers of small-sized gas turbine engines with nozzle diameters of 0.4-0.6 mm for various operating and design parameters. The study was carried out using experimental measurements, semi-empirical correlations and CFD (computational fluid dynamics) methods. The Euler approach, the volume- of- fluid (VOF) method, was used to model multiphase flows in CFD simulations. Good agreement was obtained between experimental and predicted data on the fuel coefficient and the primary spray cone angle at the nozzle outlet. Besides, the assessment of the applicability of semi-empirical techniques for the nozzle configurations under consideration is given. In the future, the flow characteristics in question (the nozzle flow rate, the fuel film thickness, and the primary spray cone angle) can be used to determine the mean diameter of the droplets (SMD) required to fully determine the boundary conditions of fuel injection when modeling combustion processes in combustion chambers of small-sized gas turbine engines.

Inlet Duct-Engine Exhaust Nozzle Airflow Matching for the Supersonic Transport

1968 ◽  
Vol 72 (690) ◽  
pp. 490-497
Author(s):  
J. B. Taylor
Keyword(s):  
Propulsion System ◽  
Operating Conditions ◽  
Design Parameters ◽  
Gas Generator ◽  
Propulsion Systems ◽  
Engine Exhaust ◽  
Supersonic Transport ◽  
Reliable Performance ◽  
Jet Nozzle ◽  
Secondary Air

Propulsion systems selected for commercial transports must provide efficient and reliable performance over a broad range of conditions. These aeroplanes are used over both short and long route segments, on non-standard days, and at a range of altitudes to meet air-line schedule requirements. This paper covers some of the design parameters that were considered in the integration of the induction system, secondary air system, jet nozzle and the basic turbojet gas generator for the SST. During recent years some of the most important gains in propulsion efficiency have resulted from the development of inlets, engines and exhaust nozzles which are matched over a broad range of operating conditions. An efficient propulsion system for a supersonic transport depends upon very close matching of these components. This, of course, requires a better understanding of the capabilities and limitations of each of these major components. For the supersonic transport, 50% or more of the gross weight will be comprised of propulsion system and fuel and less than 10% will be payload.

Design Methodology for Biomimetic Propulsion of Miniature Swimming Robots

2005 ◽  
Vol 128 (1) ◽  
pp. 36-43 ◽  
Author(s):  
Bahareh Behkam ◽  
Metin Sitti
Keyword(s):  
Energy Efficient ◽  
Silicone Oil ◽  
Design Parameters ◽  
Optimized Design ◽  
Hydrodynamic Models ◽  
Low Velocity ◽  
Propulsion Systems ◽  
New Methods ◽  
Eukaryotic Microorganisms ◽  
Pi Theorem

Miniature and energy-efficient propulsion systems hold the key to maturing the technology of swimming microrobots. In this paper, two new methods of propulsion inspired by the motility mechanism of prokaryotic and eukaryotic microorganisms are proposed. Hydrodynamic models for each of the two methods are developed, and the optimized design parameters for each of the two propulsion modes are demonstrated. To validate the theoretical result for the prokaryotic flagellar motion, a scaled-up prototype of the robot is fabricated and tested in silicone oil, using the Buckingham PI theorem for scaling. The proposed propulsion methods are appropriate for the swimming robots that are intended to swim in low-velocity fluids.

scholarly journals Flight density of the aquatic insect fauna over the water surface in the middle reaches of the Shinano River, Japan, mainly among caddisflies (Trichoptera)

Zoosymposia ◽  
2016 ◽  
Vol 10 (1) ◽  
pp. 203-213
Author(s):  
KIMIO HIRABAYASHI ◽  
ERI IKUTAMA ◽  
KOUSAKU OHKAWA ◽  
RYOICHI ARAI ◽  
TAKAOMI NOMURA ◽  
...  
Keyword(s):  
Aquatic Insects ◽  
Water Surface ◽  
Aquatic Insect ◽  
Relative Number ◽  
Insect Fauna ◽  
River Bed ◽  
Individual Number ◽  
Caddisfly Larvae ◽  
Aquatic Insect Fauna ◽  
The Individual

We focused on the relative number of flying adult caddisflies on the river surface captured by sticky board traps with the aim of elucidating differences in the distribution pattern of caddisfly larvae along the slope in the middle reaches of the Shinano River. The individual number of adult caddisflies caught increased from April and decreased from October. Even in the same middle reaches of a river, there was a large difference geographically in the species captured. Hydroptila sp. was caught mainly downstream of the Taishyobashi Bridge, Psychomyia acutipennis (Ulmer 1908) in the vicinity of the Taishyobashi Bridge, and Stenopsyche marmorata Navás 1920 upstream of the Awasabashi Bridge. It is known that the slope of the Shinano River bed suddenly becomes less and the flow rate slower in the area from the Taishyobashi Bridge to the Awasabashi Bridge, and it was shown that the species composition and number of aquatic insects caught changes with the change in the slope of the river bed.

Effect of atmospheric-pressure plasma irradiation on the surface tension of water

2022 ◽  
Author(s):  
Naoki Shirai ◽  
Takuma Kaneko ◽  
Yuto Takamura ◽  
Koichi Sasaki
Keyword(s):  
Surface Tension ◽  
Gas Phase ◽  
Atmospheric Pressure ◽  
Water Surface ◽  
Atmospheric Pressure Plasma ◽  
Marangoni Effect ◽  
Oh Radicals ◽  
Plasma Irradiation ◽  
Pressure Plasma ◽  
Trapping Agent

Abstract We have shown that measuring the surface tension is a useful scheme to examine the plasma-liquid interface in real-time. The surface tension was measured using a method based on the dispersion relation of an acoustic capillary wave excited on the water surface. The surface tension gradually increased with time, when the water surface was irradiated with the outside region of the spatial afterglow of an atmospheric-pressure plasma. The Marangoni effect associated with the localized increase in the surface tension was observed during the plasma irradiation. The surface tension decreased after the termination of the discharge. A correlation was found between the transient decrease in the surface tension and the variation of the OH radical density in the gas phase. No increase in the surface tension was observed in the solution containing a trapping agent for liquid-phase OH radicals. These experimental results suggest that OH radicals act to increase the surface tension. However, the behavior of the surface tension cannot be explained perfectly by considering only the action of OH radicals.

Development of the method of forming the shape of a reusable aerospace system, optimization of its design parameters and motion paths

2019 ◽  
Author(s):  
V.I. Buzuluk ◽  
S.M. Mikhalev
Keyword(s):  
Economic Performance ◽  
Liquid Fuel ◽  
Unit Cost ◽  
System Optimization ◽  
Design Parameters ◽  
Analysis Methodology ◽  
Starting Point ◽  
System Trajectory ◽  
Motion Paths ◽  
Payload Mass

The paper investigates a concept of an aerospace system based on air launch from subsonic twin-fuselage aircraft and on the rocket launch into orbit. We propose a scheme of aerospace system trajectory providing return to the starting point both of the carrier and the first rocket stage with liquid-fuel motors. A method for multidisciplinary calculation and optimization of the design parameters of the aerospace system and approximately optimal control of the motion of the system steps with different power units in all flight segments, as well as a feasibility study, was developed On the basis of the developed techno-economic analysis methodology, a complex of computational programs in C ++ was compiled to determine the main design parameters and characteristics. The comparative analysis of three versions of carrier aircraft and three fuel options at the first rocket stage was carried out. The analysis showed that compared to kerosene variant the hydrogen hypersonic booster made it possible to significantly increase the payload mass while the launching costs stayed the same. We compared engineering-and-economic performance of the aerospace system with “Soyuz-2.1” expendable launch vehicle. The comparison showed that the unit cost of aerospace system injection can be reduced significantly compared to an expendable carrier due to system reusability.

Defining the Ecological Coefficient of Performance for an Aircraft Propulsion System

2018 ◽  
Vol 35 (2) ◽  
pp. 171-180 ◽  
Author(s):  
Yasin Şöhret
Keyword(s):  
Performance Indicator ◽  
Propulsion System ◽  
Coefficient Of Performance ◽  
Design Parameters ◽  
Propulsion Systems ◽  
Turbojet Engine ◽  
Energy Conversion Systems ◽  
And Performance ◽  
Aircraft Propulsion System ◽  
Aircraft Propulsion

Abstract The aircraft industry, along with other industries, is considered responsible these days regarding environmental issues. Therefore, the performance evaluation of aircraft propulsion systems should be conducted with respect to environmental and ecological considerations. The current paper aims to present the ecological coefficient of performance calculation methodology for aircraft propulsion systems. The ecological coefficient performance is a widely-preferred performance indicator of numerous energy conversion systems. On the basis of thermodynamic laws, the methodology used to determine the ecological coefficient of performance for an aircraft propulsion system is parametrically explained and illustrated in this paper for the first time. For a better understanding, to begin with, the exergy analysis of a turbojet engine is described in detail. Following this, the outputs of the analysis are employed to define the ecological coefficient of performance for a turbojet engine. At the end of the study, the ecological coefficient of performance is evaluated parametrically and discussed depending on selected engine design parameters and performance measures. The author asserts the ecological coefficient of performance to be a beneficial indicator for researchers interested in aircraft propulsion system design and related topics.

NEW CONCEPTS IN SPRAYING DISPERSANTS FROM BOATS

1985 ◽  
Vol 1985 (1) ◽  
pp. 3-6
Author(s):  
Tom E. Allen
Keyword(s):  
Water Surface ◽  
High Speed ◽  
Design Parameters ◽  
Stream Velocity ◽  
New Approach ◽  
Air Stream ◽  
New Concepts ◽  
Straight Line ◽  
Coverage Rates ◽  
Wide Swath

ABSTRACT A new approach to applying chemical dispersants from boats has been developed. The equipment has a greater swath width and, thus, greater coverage rates than existing technology. Coverage rates of 2½ square miles per day per boat are likely and four or more square miles per day is possible. The method utilizes high speed fans which create a focused air stream with maximum velocities of 90 miles per hour. Dispersant is injected into and propelled by the air stream. With the air stream acting as a carrier for the dispersant, the spraying of smaller volumes of concentrate dispersant or dilute dispersant over a wide swath width is made possible. The focused air stream and dispersant impacts the water surface in approximately a straight line. The water surface is gently agitated by the air stream and liquid impact. A dispersant fan sprayer has been built and tested statically on land and demonstrated offshore on a supply vessel while spraying water. Design parameters include fan size, air stream velocity, expected swath width, and concentrate (low volume) versus dilute (large volume) spraying.

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