Experimental optimization of hydrodynamic performance of catamarans using hydrofoil element

2018 ◽  
Vol 233 (2) ◽  
pp. 488-501 ◽  
Author(s):  
Amin Najafi ◽  
Taghi Aliakbari ◽  
Seyed Abolfazl Hashemi
Keyword(s):  
Experimental Data ◽  
Fuel Consumption ◽  
Marine Environment ◽  
High Speed ◽  
Hydrodynamic Performance ◽  
Environment Pollution ◽  
Fuel Cost ◽  
Energy Consumption Reduction ◽  
Consumption Reduction

Daily increase in fuel cost and also marine environment pollution tends designers and engineers to design and optimize based on reducing losses and energy consumption. Reduction of fuel consumption and marine environment pollution are categorized in high priority problems in design of new vessels and optimization of current ones. Using hydrofoil between two hulls is one of the best strategies in optimization cycle of fuel consumption of catamarans. HYSUCAT comes from “Hydrofoil Supported Catamarans” and stands for a vessel which is composed of a catamaran hull and hydrofoils mounted between two hulls. These hydrofoils tolerate part of hull weight in high speed and decrease wetted surface of vessel. This element reduces drag of vessel and consequently fuel consumption by decreasing the wetted surface. This research deals with determination of a suitable hydrofoil section to reduce drag and increase stability of a catamaran vessel using experimental data. Full-scale foils were constructed and mounted on a vessel in continue, and its performance was examined in sea tests. Determining the best section and also the most suitable position for mounting the foil is a novel study in the field of hydrodynamics of catamaran vessels.

scholarly journals FEATURES OF POWER DETERMINATION OF AUXILIARY-EMERGENCY DRIVE MOTION OF A SHIP WITH A COMBINED DIESEL-ELECTRIC POWER PLANT

2020 ◽  
Vol 4 (52) ◽  
pp. 8-16
Author(s):  
A. Rak ◽  
◽  
V. Busher ◽  
O. Glazeva ◽  
◽  
...  
Keyword(s):  
Fuel Consumption ◽  
High Speed ◽  
Electric Capacity ◽  
Optimal Load ◽  
High Speed Diesel ◽  
Harmful Emissions ◽  
Diesel Generators ◽  
Main Engine ◽  
Engine Power

Purpose. The paper compares the traditional method of calculating the parameters of electric motion of ships in auxiliary emergency modes at low speeds of the vessel with another, simplified because it does not require the use of a large number of diagrams to determine the resistance of the vessel. But according to a simplified method for this example – a container ship with a capacity of 16,000 containers with the main engine capacity of 61776 kW, a synchronous machine with a capacity of up to 6 MW in engine mode, and three diesel generators with an electric capacity of 3187 kW – 39 % more power is obtained. Own experience of operation of the vessel in modes with electric movement – loading of diesel generators in this mode on the vessel about 70 % that is received by calculations. Thus, when upgrading the propulsion system or designing new vessels, it is advisable to compare the results of two calculations of the power of diesel generators at the limit of the minimum stable speed of the main engine and choose the larger of the results. Methodology. Comparison of specific and absolute fuel consumption, made on the basis of known approximation polynomials for low- and high-speed types of diesel of the company at auxiliary emergency movement shows that at the movement from high-speed diesel generators MAK8M32S fuel consumption decreases by 24 %, then at the maintenance of the main engine 12 RTflex-96C from WÄRTSILÄ-SULZER. Results. Therefore, the use of electric motion allows you to save engine power of the main engine, reduce fuel consumption. This ratio is observed on most maritime transport vessels. And given that diesel generators operate at almost optimal load, and the main engine – at idle, electric motion provides a significant reduction in harmful emissions into the atmosphere. The latter is also true for a ship where the synchronous engine is located behind the main engine, although fuel consumption, in this case, increases by 32 %. Figures 9, tables 6, references 15.

scholarly journals EXPERIMENTAL RESULTS OF FUEL CONSUMPTIONS CONSIDERING THE SPEEDS OF CITY BUSES

2021 ◽  
pp. 72-80
Author(s):  
S.V. Ilyanov ◽  
◽  
N.A. Kuzmin ◽  
G.V. Borisov ◽  
◽  
...  
Keyword(s):  
Mathematical Models ◽  
Fuel Consumption ◽  
Analytical Method ◽  
High Speed ◽  
Experimental Studies ◽  
Road Transport ◽  
Operating Conditions ◽  
Motor Vehicles ◽  
Actual Distribution

At the moment, there is a large number of dissertations and scientific works covering the issues of traction-speed and fuel-economic characteristics of vehicles, the results of which are presented in the form of: regression models, approximating dependencies, mathematical models based on multivariate analysis, including a number of additional coefficients. In this connection, the use of the results of these works in practice is limited, since it requires high qualifications of the МTЕ personnel and the use of special software and hardware. At the same time, at the department “Automobile transport” NSTU named after R. E. Alekseev developed a probabilistic-analytical method for predicting fuel consumption by road trains, considering the high-speed mode of movement, which shows a high convergence of results with actual average speeds only for uniform movement of buses with a constant average speed, which is not applicable to the assessment of fuel consumption of city buses. Based on the hypothesis put forward on the applicability of the Weibull-Gnedenko distribution for calculating the average speeds of city buses and the normal distribution for calculating accelerations during movement, the tasks of this study are formulated, expressed in the development of mathematical models reflecting the dependences of speeds and accelerations during bus movement in urban operating conditions, for planning their fuel consumption. To solve the set tasks, the following experimental studies were carried out: determination of the average coefficient of total road resistance; the actual distribution of speeds and accelerations when driving city buses; determination of the average actual value of fuel consumption when the bus is moving and when idle at stopping points. Based on the results of processing experimental studies, the possibility of using the Weibull-Gnedenko law to describe the actual speeds in urban conditions and the normal law to describe accelerations when driving city buses was confirmed, which allows planning fuel consumption using the analytical apparatus of the theory of probability and mathematical statistics and using the developed methodology in practice of motor transport enterprises. Based on experimental studies and theoretical studies in this area, an analytical method for planning fuel consumption for city buses, considering the speed of their movement, has been developed, which allows planning fuel consumption without additional experiments. Carrying out such studies for other types of motor vehicles and assessing unaccounted for indicators of road, transport and natural-climatic operating conditions will create a generalized analytical method for planning fuel consumption by vehicles in various operating conditions.

Determination of the optimal position of grain crusher boot screen of the impulse-reflective action

10.12737/2436 ◽  
2014 ◽  
Vol 8 (4) ◽  
pp. 76-81
Author(s):  
Булатов ◽  
Sergey Bulatov ◽  
Савиных ◽  
Petr Savinykh ◽  
Миронов ◽  
...  
Keyword(s):  
Energy Consumption ◽  
Minimum Energy ◽  
Point Of View ◽  
Optimal Position ◽  
Energy Consumption Reduction ◽  
Consumption Reduction ◽  
Refinement Process ◽  
Consumption Change ◽  
The Impact

We have developed an experimental setup of corn crusher of shock-reflective action. The experimental data on the impact of the loading windows location of corn crusher of shock-reflective effect on its activity were obtained. Their analyses were carried out and we identified the optimal location of the loading window, from the point of view of the of energy consumption reduction of grain refinement process. The authors studied the influence of feed delivery through the lower, upper and both loading windows simultaneously. According to the results of the experiments, we constructed graphs of energy consumption change, depending on the capacity of the crusher, during the loading the crushed feed through the top, bottom and both windows. As a result of this work it was founded that: the lowest cost crusher throughput 90 kg per hour are observed, while loading the feed through both windows; increasing the capacity over 90 kg per hour implies a sharp increase in power consumption, when applying the feed through both windows, and minimal consumption - when filing through the upper window; minimum energy fall is when feeding the feed through the top of window and hitting speed of n=2900 ... 5100 min-1. Thus revealed, that in order to reduce the energy consumption for a finished product, we must conduct further studies at loading the feed through the top window, and the rotor speed must be within n=2900 ... 5100 min-1.

Equilibrium Sorptions in Heterogeneous Ion Exchange Membranes

1992 ◽  
Vol 57 (9) ◽  
pp. 1905-1914
Author(s):  
Miroslav Bleha ◽  
Věra Šumberová
Keyword(s):  
Experimental Data ◽  
Ion Exchange ◽  
Total Content ◽  
Distribution Coefficients ◽  
Exchange Capacity ◽  
Ion Exchange Membranes ◽  
Ion Exchange Capacity ◽  
Equilibrium Sorption ◽  
Inhomogeneity Factor

The equilibrium sorption of uni-univalent electrolytes (NaCl, KCl) in heterogeneous cation exchange membranes with various contents of the ion exchange component and in ion exchange membranes Ralex was investigated. Using experimental data which express the concentration dependence of equilibrium sorption, validity of the Donnan relation for the systems under investigation was tested and values of the Glueckauf inhomogeneity factor for Ralex membranes were determined. Determination of the equilibrium sorption allows the effect of the total content of internal water and of the ion-exchange capacity on the distribution coefficients of the electrolyte to be determined.

Sampling, Preservation and Counting of Samples II: Zooplankton

2017 ◽  
Author(s):  
Peter H. Wiebe ◽  
Ann Bucklin ◽  
Mark Benfield
Keyword(s):  
Genetic Analysis ◽  
High Speed ◽  
Morphological Analysis ◽  
Taxonomic Composition ◽  
Sampling Techniques ◽  
Sample Analysis ◽  
Sample Preservation ◽  
The Past ◽  
Plankton Collection

This chapter reviews traditional and new zooplankton sampling techniques, sample preservation, and sample analysis, and provides the sources where in-depth discussion of these topics is addressed. The net systems that have been developed over the past 100+ years, many of which are still in use today, can be categorized into eight groups: non-opening/closing nets, simple opening/closing nets, high-speed samplers, neuston samplers, planktobenthos plankton nets, closing cod-end samplers, multiple net systems, and moored plankton collection systems. Methods of sample preservation include preservation for sample enumeration and taxonomic morphological analysis, and preservation of samples for genetic analysis. Methods of analysis of zooplankton samples include determination of biomass, taxonomic composition, and size by traditional methods; and genetic analysis of zooplankton samples.

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