PULSED COMBUSTION OF FUEL-AIR MIXTURE IN THE CAVITY UNDER THE BOAT BOTTOM: SIMULATION AND OUTDOOR TESTS

2020 ◽  
Author(s):  
S. M. FROLOV ◽  
◽  
S. V. PLATONOV ◽  
K. A. AVDEEV ◽  
V. S. AKSENOV ◽  
...  
Keyword(s):  
Direct Contact ◽  
Hydrodynamic Drag ◽  
Atmospheric Air ◽  
Exhaust Gases ◽  
Gas Lubrication ◽  
Gas Cavity

For reducing the hydrodynamic drag of a boat, a gas cavity can be made under the boat bottom, which will partially isolate the bot- tom from direct contact with water and provide ¤gas lubrication¥ by forced supply of atmospheric air or exhaust gases from a boat motor.

OUTDOOR TESTS OF A TOWED BOAT MODEL WITH FUEL COMBUSTION IN A BOTTOM CAVITY

2020 ◽  
Author(s):  
S. M. FROLOV ◽  
◽  
S. V. Platonov ◽  
K. A. AVDEEV ◽  
V. S. AKSENOV ◽  
...  
Keyword(s):  
Drag Force ◽  
Direct Contact ◽  
Propulsion System ◽  
Hydrodynamic Drag ◽  
Atmospheric Air ◽  
System A ◽  
Bottom Cavity ◽  
Gas Cavity ◽  
System Power ◽  
Gas Supply

To reduce the hydrodynamic drag force to the movement of the boat, an artificial gas cavity is organized under its bottom. Such a cavity partially insulates the bottom from direct contact with water and provides “gas lubrication” by means of forced supply of atmospheric air or exhaust gases from the main propulsion system. A proper longitudinal and transverse shaping of the gas cavity can significantly (by 20%-30%) reduce the hydrodynamic drag of the boat at low (less than 3%) consumption of the propulsion system power for gas supply.

Effect of Viscoelasticity of PVA Brush on Friction during Post-CMP Cleaning: A Guideline for Nodule Configuration

2014 ◽  
Vol 219 ◽  
pp. 148-152 ◽  
Author(s):  
Y. Hara ◽  
T. Sanada ◽  
A. Fukunaga ◽  
H. Hiyama
Keyword(s):  
Direct Contact ◽  
Chemical Mechanical Planarization ◽  
Three Dimensional ◽  
Hydrodynamic Drag ◽  
Trial And Error ◽  
New Materials ◽  
Friction Forces ◽  
Drag Forces ◽  
Lubrication Characteristics

The application of new materials and three-dimensional structures are being used to achieve next-generation semiconductor devices. Hence, the role of the chemical-mechanical planarization (CMP) process has gained importance. Polyvinyl acetal (PVA) brushes are widely used as scrubbers during post-CMP cleaning. However, the mechanisms of brush scrubber cleaning are still a matter of debate because direct observation is difficult. Many researchers have proposed the removal mechanisms that operate during brush cleaning based on investigations of the forces acting on particles, friction, and the lubrication characteristics. Hydrodynamic drag forces and direct contact between the brush and the particles have been proposed as cleaning mechanisms [1–5]. Philipossian et al. [6] and Sun et al. [7] focused on the brush design and suggested that the existence of nodules or eccentricity of the roller brush had a significant effect on the friction. The friction system between the roller brush and the surface is complex because of the collision of nodules with the surface. Hence, the shapes of the nodules have been designed through trial and error. In this study, we focus on the friction of a single nodule to investigate the role of nodules in roller brush cleaning. The normal and friction forces are measured during brush sliding. In particular, we focus on the viscoelastic properties of a PVA brush and discuss its effects on friction.

Calculating the Speed of Sound in an Engine Exhaust Stream

2008 ◽  
Author(s):  
Justin D. Keske ◽  
Jason R. Blough
Keyword(s):  
Chemical Composition ◽  
Speed Of Sound ◽  
Gasoline Engine ◽  
Combustion Process ◽  
Exhaust Gas ◽  
Gas Temperature ◽  
Fuel Blend ◽  
Atmospheric Air ◽  
Exhaust Gases ◽  
Exhaust Stream

The actual speed of sound in the exhaust medium of an engine plays an extensive role in the noise attenuation characteristics of the engine’s muffler system. For 2-stroke engine applications, the speed of sound in the exhaust gas also greatly affects how the expansion chamber is tuned to maintain maximum power output. The combustion process in an engine creates exhaust gases that differ from the composition of atmospheric air. This difference in chemical composition and humidity content yield a different density and ratio of specific heats. These ultimately yield different sound speeds in the exhaust gases compared to atmospheric air. This paper performs a full chemical analysis of the combustion process in an internal combustion gasoline engine to yield the chemical composition of the of the exhaust gases. An algorithm is written to calculate the speed of sound in the exhaust stream. The inputs of the algorithm include measurements of temperature, pressure, and relative humidity of the ambient intake air, specification of the gasoline/ethanol fuel blend, and a direct measurement of the exhaust gas temperature. Comparisons are made between sound speed approximation calculations based on air to calculations obtained by the algorithm.

scholarly journals Загрязнение воздуха твердыми частицами в пяти точках Владивостока (морской и автомобильный транспорт)

2020 ◽  
Vol 44 (3) ◽  
pp. 93-103
Author(s):  
Hong Hai Le
Keyword(s):  
Air Pollution ◽  
Solid Particles ◽  
Traffic Load ◽  
Particulate Emissions ◽  
Traffic Flows ◽  
Atmospheric Air ◽  
Exhaust Gases ◽  
The Impact ◽  
The City ◽  
Port Areas

Проведена оценка влияния автомобильных и судовых транспортных потоков на общую концентрацию взвешенных частиц (РМ) в атмосферном воздухе города Владивостока. В авторском эксперименте делались замеры в пяти контрольных точках, различных по орографическим характеристикам и уровню транспортной нагрузки. Было учтено загрязнение атмосферного воздуха твердыми частицами, которые содержатся в отработанных газах (ОГ) судовых энергетических установок (ССЭУ). Определено, что транспортные потоки – один из основных источников РМ в атмосферном воздухе Владивостока. Дифференцированная оценка уровня загрязнения РМ транспортными потоками позволила определить диапазон выбросов РМ от ОГ ССЭУ в атмосферу (в зависимости от орографических и климатических характеристик): 15–90%. В двух районах города, наиболее близких к портовым зонам, этот показатель оказался выше почти в 2 раза, чем в контрольной точке, наиболее удаленной от портовых зон. Ключевые слова: выбросы твердых частиц, водный транспорт, отработанные газы судовых установок, концентрация частиц в воздухе, воздух портового города, загрязнение воздуха частицами. The impact of automobile and maritime traffic flows on the total concentration of suspended particles (RM) in the atmospheric air of the city of Vladivostok was assessed. In the experiment, measurements were made at five control points with different orographic characteristics and levels of traffic load intensity. Also, air pollution with solid particles emitted by exhaust gases (exhaust) of marine power plants (SSEU) was taken into account. It is determined that traffic flows are one of the main sources of RM in the atmospheric air of the city of Vladivostok. A differentiated assessment of the level of PM pollution by traffic flows showed that depending on the geographical and climatic characteristics, overall contribution of PM from the OG SSEU to the urban atmosphere is in the range of 15–90%. At two spots closest to the port areas, this value was 70% and 80%. This indicator is almost two times higher than at the control point most remote from port areas. Keywords: particulate emissions, water transport, exhaust gases from ship installations, particle concentration in air, port city air, particle air pollution.

Waste Heat Recovery by Organic Rankine Cycle (ORC) for Moist Exhaust Gases From Paper Industry

2017 ◽  
Author(s):  
Wamei Lin ◽  
Lars Nilsson ◽  
Raffaele Malutta
Keyword(s):  
Water Vapor ◽  
Latent Heat ◽  
Direct Contact ◽  
Waste Heat ◽  
Paper Industry ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Drying Process ◽  
Exhaust Gases

Large potential exists in recovering waste heat from paper industry processes and machinery. If the overall energy efficiency would be increased, it could lead to significant fuel savings and greenhouse gas emission reduction. The organic Rankine cycle (ORC) system is a very strong candidate for converting low-grade waste heat into power. However, there is a lot of water vapor containing latent heat in the exhaust gases from the drying process in the paper industry. Thus, the aim of this research work is to increase the efficiency of the ORC system by recovering not only the sensible heat but also the latent heat from the exhaust gases in the paper drying process. In order to recover the latent heat from the moist exhaust gases, one idea of this article is to introduce a direct contact condensing unit into the ORC system. The performance of ORC system with the direct contact condensing unit was analyzed by using the CHEMCAD software. A case study was conducted based on data of the exhaust gases from a tissue production / drying machine. Latent heat will be recovered when the evaporating temperature of the ORC working fluid is lower than the dew point of the water vapor in the exhaust gases. The results showed that the available heat load was increased when the evaporating temperature was reduced. Furthermore, a performance comparison of the ORC systems with and without the direct contact condensing unit was carried out in the case study as well. The results showed that the ORC system with the direct contact condensing unit not only could recover latent heat from the water vapor in the exhaust gases but also could have a small size and small volume evaporator in the ORC system.

Saturn's E, G and F rings: modulated by the plasma sheet

1984 ◽  
Vol 75 ◽  
pp. 597
Author(s):  
E. Grün ◽  
G.E. Morfill ◽  
T.V. Johnson ◽  
G.H. Schwehm
Keyword(s):  
Solar Wind ◽  
Direct Contact ◽  
Transport Processes ◽  
Time Variable ◽  
Dust Particles ◽  
Spatial Diffusion ◽  
Drag Forces ◽  
Orbit Perturbation ◽  
Time Variations ◽  
F Ring

ABSTRACTSaturn's broad E ring, the narrow G ring and the structured and apparently time variable F ring(s), contain many micron and sub-micron sized particles, which make up the “visible” component. These rings (or ring systems) are in direct contact with magnetospheric plasma. Fluctuations in the plasma density and/or mean energy, due to magnetospheric and solar wind processes, may induce stochastic charge variations on the dust particles, which in turn lead to an orbit perturbation and spatial diffusion. It is suggested that the extent of the E ring and the braided, kinky structure of certain portions of the F rings as well as possible time variations are a result of plasma induced electromagnetic perturbations and drag forces. The G ring, in this scenario, requires some form of shepherding and should be akin to the F ring in structure. Sputtering of micron-sized dust particles in the E ring by magnetospheric ions yields lifetimes of 102to 104years. This effect as well as the plasma induced transport processes require an active source for the E ring, probably Enceladus.

Worker Protection Standard: Owner and Immediate Family Exemption

EDIS ◽  
2016 ◽  
Vol 2016 (7) ◽  
Author(s):  
Frederick M. Fishel ◽  
Tatiana Sanchez
Keyword(s):  
Direct Contact ◽  
Family Members ◽  
Agricultural Workers ◽  
Federal Regulation ◽  
Fact Sheet ◽  
Agricultural Plants

The Worker Protection Standard (WPS) is a Federal regulation designed to protect agricultural workers (people involved in the production of agricultural plants) and pesticide handlers (people mixing, loading, or applying pesticides or doing other tasks involving direct contact with pesticides).There are certain exemptions in the WPS rule that have been revised pertaining to agricultural establishment owners and their immediate family members. This fact sheet explains these new provisions.

Worker Protection Standard: Information at a Central Location

EDIS ◽  
2016 ◽  
Vol 2016 (7) ◽  
Author(s):  
Frederick M. Fishel ◽  
Tatiana Sanchez
Keyword(s):  
Direct Contact ◽  
Agricultural Workers ◽  
Specific Information ◽  
Federal Regulation ◽  
Central Location ◽  
Agricultural Pesticides ◽  
Full Implementation ◽  
Standard Information ◽  
Agricultural Plants ◽  
General Guidance

The Worker Protection Standard (WPS) is a Federal regulation designed to protect agricultural workers (people involved in the production of agricultural plants) and pesticide handlers (people mixing, loading, or applying pesticides or doing other tasks involving direct contact with pesticides). It has been in full implementation since 1995. This document provides general guidance to help you comply with the requirements of the Federal Worker Protection Standard (WPS) for agricultural pesticides, 40 CFR part 170, as amended in 2015. This document addresses specific information that agricultural establishments must display at a central location for their employees.

Managing total reduced sulfur emissions at a Canadian kraft pulp mill

TAPPI Journal ◽  
2016 ◽  
Vol 15 (4) ◽  
pp. 265-272 ◽  
Author(s):  
ROHAN BANDEKAR ◽  
JIM FREDERICK ◽  
JAROSLAV STAVIK
Keyword(s):  
Direct Contact ◽  
Black Liquor ◽  
Pulp Mill ◽  
Packed Bed ◽  
Average Value ◽  
Emission Limit ◽  
Total Reduced Sulfur ◽  
Reduced Sulfur ◽  
Air Ingress ◽  
Solids Content

This study addresses the challenges a dissolving-grade pulp mill in Canada faced in 2014 in meeting its total reduced sulfur (TRS) gas emission limit. These emissions from the recovery boiler exit are controlled by passing the boiler exit gas through a TRS scrubber system. The mill employs a cyclonic direct contact evaporator to concentrate black liquor to firing solids content. The off-gases from the direct contact evaporator flow to the effluent gas control system that consists of a venturi scrubber, a packed bed scrubber, and a heat recovery unit. Emissions of TRS greater than the regulated limit of 15 ppm were observed for a 4-month period in 2014. The level of emissions measured during this period was significantly higher than about 12 ppm, the expected average value based on historic experience. The problem persisted from mid-June 2014 until the annual mill shutdown in October 2014. The main TRS components detected and the performance of the Teller scrubber in capturing them are examined. Other potential causes for these emissions are identified, including mechanical problems such as broken packing in the TRS packed bed scrubber, broken baffle plates in the scrubber, and cyclone evaporator leaks causing air ingress. Repairs were carried out during the mill shutdown, which eliminated the TRS emissions problem.

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