ENABLING TECHNOLOGY AND THE NAVAL ARCHITECT 1860-2010

2021 ◽  
Vol 152 (A2) ◽  
Author(s):  
I Buxton

Enabling technology permits the naval architect to do more with fewer resources, increasing output, decreasing cost and improving productivity, with the resulting benefits being widely distributed in a worldwide economy. For example a bulk carrier’s energy consumption per ton-mile today is less than 3% of what it was a century and half ago – due to more efficient machinery, larger hulls with lower resistance per ton and improved propulsive efficiency, yet with higher speed and shorter port times.

2021 ◽  
Vol 156 (A2) ◽  
Author(s):  
I Buxton

I have a brief comment to contribute: “This is a thorough review of the technical changes over the last 150 years in the Marine Sector. Even more interesting the author has linked these with the changing market and business drivers over that period. It also illustrates how the aggregation of all the individual changes represent several revolutions in the sector. Can I ask the author to now wind the story forwards and give his view of the future and what the marriage of “Technology Push” and “Market Pull” is likely to hold in store for the next 150 years. However disconcerting it might seem - the rate of change will not stop – the opportunities are legion”.


2021 ◽  
Vol 285 ◽  
pp. 07023
Author(s):  
Vladimir Pryadkin ◽  
Artyom Artyomov ◽  
Pavel Kolyadin ◽  
Nikolay Bakach

The article deals with the problem of reducing energy consumption when moving mobile power sources on deformable support bases. On basis of experimental studies using test-bench equipment, the main output parameters of 1020x420-18 tire of Bel-79 model were determined. Analysis of the results obtained made it possible to determine an optimal range of intra-tire pressure, when the realized propulsive efficiency takes maximum values, and energy consumption for selfpropulsion is minimal.


2000 ◽  
Vol 122 (3) ◽  
pp. 614-618 ◽  
Author(s):  
Motomu Nakashima ◽  
Kyosuke Ono

In our previous paper, we proposed a numerical method based on the discrete vortex method for a bending propulsion mechanism of fish or cetaceans in water, and we demonstrated its validity by comparing the results with an experiment using a three joint bending propulsion mechanism. In this paper, using this numerical method, we will analyze the characteristics of the thrust, energy consumption, and propulsive efficiency of a three joint bending propulsion mechanism in terms of normalized propulsive speed and the phase differences of the adjacent joints. We found that the thrust decreases due to the increase in the lift force as the normalized propulsive speed increases when all the joints move in phase. We also found that the propulsive efficiency has a maximum value when the normalized propulsive speed is 0.8 and when all the phase differences between the joints are 100 degrees. [S0098-2202(00)01203-7]


Author(s):  
Shahzeen Z. Attari ◽  
Michael L. DeKay ◽  
Cliff I. Davidson ◽  
Wandi Bruine de Bruin

ICCTP 2009 ◽  
2009 ◽  
Author(s):  
Shunquan Huang ◽  
Siqin Yu ◽  
Zhongmin Liu

2020 ◽  
Vol 39 (4) ◽  
pp. 5449-5458
Author(s):  
A. Arokiaraj Jovith ◽  
S.V. Kasmir Raja ◽  
A. Razia Sulthana

Interference in Wireless Sensor Network (WSN) predominantly affects the performance of the WSN. Energy consumption in WSN is one of the greatest concerns in the current generation. This work presents an approach for interference measurement and interference mitigation in point to point network. The nodes are distributed in the network and interference is measured by grouping the nodes in the region of a specific diameter. Hence this approach is scalable and isextended to large scale WSN. Interference is measured in two stages. In the first stage, interference is overcome by allocating time slots to the node stations in Time Division Multiple Access (TDMA) fashion. The node area is split into larger regions and smaller regions. The time slots are allocated to smaller regions in TDMA fashion. A TDMA based time slot allocation algorithm is proposed in this paper to enable reuse of timeslots with minimal interference between smaller regions. In the second stage, the network density and control parameter is introduced to reduce interference in a minor level within smaller node regions. The algorithm issimulated and the system is tested with varying control parameter. The node-level interference and the energy dissipation at nodes are captured by varying the node density of the network. The results indicate that the proposed approach measures the interference and mitigates with minimal energy consumption at nodes and with less overhead transmission.


2019 ◽  
pp. 53-65
Author(s):  
Renata Domingos ◽  
Emeli Guarda ◽  
Elaise Gabriel ◽  
João Sanches

In the last decades, many studies have shown ample evidence that the existence of trees and vegetation around buildings can contribute to reduce the demand for energy by cooling and heating. The use of green areas in the urban environment as an effective strategy in reducing the cooling load of buildings has attracted much attention, though there is a lack of quantitative actions to apply the general idea to a specific building or location. Due to the large-scale construction of high buildings, large amounts of solar radiation are reflected and stored in the canyons of the streets. This causes higher air temperature and surface temperature in city areas compared to the rural environment and, consequently, deteriorates the urban heat island effect. The constant high temperatures lead to more air conditioning demand time, which results in a significant increase in building energy consumption. In general, the shade of the trees reduces the building energy demand for air conditioning, reducing solar radiation on the walls and roofs. The increase of urban green spaces has been extensively accepted as effective in mitigating the effects of heat island and reducing energy use in buildings. However, by influencing temperatures, especially extreme, it is likely that trees also affect human health, an important economic variable of interest. Since human behavior has a major influence on maintaining environmental quality, today's urban problems such as air and water pollution, floods, excessive noise, cause serious damage to the physical and mental health of the population. By minimizing these problems, vegetation (especially trees) is generally known to provide a range of ecosystem services such as rainwater reduction, air pollution mitigation, noise reduction, etc. This study focuses on the functions of temperature regulation, improvement of external thermal comfort and cooling energy reduction, so it aims to evaluate the influence of trees on the energy consumption of a house in the mid-western Brazil, located at latitude 15 ° S, in the center of South America. The methodology adopted was computer simulation, analyzing two scenarios that deal with issues such as the influence of vegetation and tree shade on the energy consumption of a building. In this way, the methodological procedures were divided into three stages: climatic contextualization of the study region; definition of a basic dwelling, of the thermophysical properties; computational simulation for quantification of energy consumption for the four facade orientations. The results show that the façades orientated to north, east and south, without the insertion of arboreal shading, obtained higher values of annual energy consumption. With the adoption of shading, the facades obtained a consumption reduction of around 7,4%. It is concluded that shading vegetation can bring significant climatic contribution to the interior of built environments and, consequently, reduction in energy consumption, promoting improvements in the thermal comfort conditions of users.


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