scholarly journals Preliminary Design of a Wind Driven Vessel Dedicated to Hydrogen Production

2017 ◽  
Author(s):  
Jean-Christophe Gilloteaux ◽  
Aurélien Babarit
Keyword(s):  
Mathematical Model ◽  
Wind Speed ◽  
High Performance ◽  
Turbine Disk ◽  
Preliminary Design ◽  
Aerodynamic Coefficients ◽  
Ship Hulls ◽  
Water Turbine ◽  
Existing Data ◽  
Innovative Concept

An innovative concept of harnessing wind energy is presented. The concept consists of a wind driven ship equipped with a hydro-generator that converts the kinetic energy of the water flow into electricity. The electricity is then converted into hydrogen by electrolysis. In the present study the use of a Flettner rotor is considered to propel the ship. A mathematical model of the hydrogen producing ship is developed based on existing data for high performance ship hulls and aerodynamic coefficients of existing Flettner rotors. The design is optimized with respect to the axial induction velocity through the water turbine disk. Results indicate that a 22m long vessel could produce 200 kW while a 80 m long vessel is able to generate 1 MW of mechanical power both for a true wind speed of 8 m/s.

scholarly journals Analysis of Performance of the Wind-Driven Pulverizing Aerator Based on Average Wind Speeds in the Conditions of Góreckie Lake

Energies ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2796
Author(s):  
Andrzej Osuch ◽  
Ewa Osuch ◽  
Stanisław Podsiadłowski ◽  
Piotr Rybacki
Keyword(s):  
Mathematical Model ◽  
Wind Speed ◽  
Water Pump ◽  
Average Wind Speed ◽  
Flow Rates ◽  
Wind Speeds ◽  
Average Wind ◽  
Flow Through ◽  
Analysis Of Performance ◽  
Research Period

In the introduction to this paper, the characteristics of Góreckie lake and the construction and operation of the wind-driven pulverizing aerator are presented. The purpose of this manuscript is to determine the efficiency of the pulverizing aerator unit in the windy conditions of Góreckie Lake. The efficiency of the pulverization aerator depends on the wind conditions at the lake. It was necessary to conduct thorough research to determine the efficiency of water flow through the pulverization segment (water pump). It was necessary to determine the rotational speed of the paddle wheel, which depended on the average wind speed. Throughout the research period, measurements of hourly average wind speed were carried out. It was possible to determine the efficiency of the machine by developing a dedicated mathematical model. The latest method was used in the research, consisting of determining the theoretical volumetric flow rates of water in the pulverizing aerator unit, based on average hourly wind speeds. Pulverization efficiency under the conditions of Góreckie Lake was determined based on 6600 average wind speeds for spring, summer and autumn, 2018. Based on the model, the theoretical efficiency of the machine was calculated, which, under the conditions of Góreckie Lake, amounted to 75,000 m3 per year.

Influence of Tooth Errors and Truing Principles of Grinding Wheel Abrasion for Machining Arc Enveloping Worm

2013 ◽  
Vol 652-654 ◽  
pp. 2153-2158
Author(s):  
Wu Ji Jiang ◽  
Jing Wei
Keyword(s):  
Mathematical Model ◽  
Case Studies ◽  
High Precision ◽  
High Performance ◽  
New Method ◽  
Grinding Wheel ◽  
Grinding Process ◽  
The Mathematical Model

Controlling the tooth errors induced by the variation of diameter of grinding wheel is the key problem in the process of ZC1 worm grinding. In this paper, the influence of tooth errors by d1, m and z1 as the grinding wheel diameter changes are analyzed based on the mathematical model of the grinding process. A new mathematical model and truing principle for the grinding wheel of ZC1 worm is presented. The shape grinding wheel truing of ZC1 worm is carried out according to the model. The validity and feasibility of the mathematical model is proved by case studies. The mathematical model presented in this paper provides a new method for reducing the tooth errors of ZC1 worm and it can meet the high-performance and high-precision requirements of ZC1 worm grinding.

scholarly journals ANALYTICAL METHODS FOR CALCULATING FAN AERODYNAMICS

2015 ◽  
Vol 55 (6) ◽  
pp. 373
Author(s):  
Jan Dostal ◽  
Jan Kuzel
Keyword(s):  
Mathematical Model ◽  
Analytical Methods ◽  
Preliminary Design ◽  
Computer Programme ◽  
Aerospace Research ◽  
Model Based ◽  
The Creation ◽  
The Mathematical Model ◽  
Measuring Unit

This paper presents results obtained between 2010 and 2014 in the field of fan aerodynamics at the Department of Composite Technology at the VZLÚ aerospace research and experimental institute in Prague – Letnany. The need for rapid and accurate methods for the preliminary design of blade machinery led to the creation of a mathematical model based on the basic laws of turbomachine aerodynamics. The mathematical model, the derivation of which is briefly described below, has been encoded in a computer programme, which enables the theoretical characteristics of a fan of the designed geometry to be determined rapidly. The validity of the mathematical model is assessed continuously by measuring model fans in the measuring unit, which was developed and manufactured specifically for this purpose. The paper also presents a comparison between measured characteristics and characteristics determined by the mathematical model as the basis for a discussion on possible causes of measured deviations and calculation deviations.

scholarly journals CubeSat Development for Lightning Flashes Detection: RaioSat Project

2020 ◽  
pp. 80-93
Author(s):  
Antonio Cassiano Julio Filho ◽  
Auro Tikami ◽  
Elaine de Souza Ferreira de Paula ◽  
Jhonathan Murcia Piñeros ◽  
George Favale Fernandes ◽  
...  
Keyword(s):  
Preliminary Analysis ◽  
Short Range ◽  
Numerical Models ◽  
Human Action ◽  
Severe Weather ◽  
Preliminary Design ◽  
The World ◽  
Prediction Techniques ◽  
Operational Modes ◽  
Existing Data

Annually, severe weather phenomena are responsible for tens of thousands of deaths and tens of billions of dollars of damage around the world. In Brazil, unlike other hydrometeorological events, severe atmospheric events are random and, therefore, do not have a sociospatial pattern. Because of that, there is a significant motivation to improve the prediction techniques for this kind of events, using high resolution numerical models. A large amount of high-quality observational data is required, including lightning data in a very short-range. In addition, the detection of lightning flashes produced by storms is important for a wide variety of applications and in some areas of scientific research, which include the understanding of the human action on the climate and how the climate change can affect the behavior of storms in long range. One method to monitor the lightning flashes is the implementation of sensors in satellites to obtain data. In this sense, the objective of the RaioSat project is to develop national technology for detecting lightning flashes from the space, in order to complement the existing data from the ground detection network, BrasilDAT. The main objective of this article is to present a methodology for the development of the RaioSat mission including some parts of the preliminary design and operational modes. Additionally, the article describes the expected results and the continuity of the project and a preliminary analysis of a constellation for future projects.

scholarly journals Enhanced Central System of the Traversing Rod for High-Performance Rotor Spinning Machines

2017 ◽  
Vol 17 (1) ◽  
pp. 27-34 ◽  
Author(s):  
Jan Valtera ◽  
Petr Žabka ◽  
Jaroslav Beran
Keyword(s):  
Mathematical Model ◽  
High Performance ◽  
Mechanical Energy ◽  
Optimal Number ◽  
Dynamic Force ◽  
Rectilinear Motion ◽  
Central System ◽  
Rotor Spinning ◽  
New System

Abstract The paper deals with the improvement of central traversing system on rotor spinning machines, where rectilinear motion with variable stroke is used. A new system of traversing rod with implemented set of magnetic-mechanical energy accumulators is described. Mathematical model of this system is analysed in the MSC. Software Adams/View and verified by an experimental measurement on a real-length testing rig. Analysis results prove the enhancement of devised traversing system, where the overall dynamic force is reduced considerably. At the same time, the precision of the traversing movement over the machine length is increased. This enables to increase machine operating speed while satisfying both the maximal tensile strength of the traversing rod and also output bobbin size standards. The usage of the developed mathematical model for determination of the optimal number and distribution of accumulators over the traversing rod of optional parameters is proved. The potential of the devised system for high-performance rotor spinning machines with longer traversing rod is also discussed.

scholarly journals Preliminary Sailplane Design Using MDO And Multi-Fidelity Analysis

2021 ◽  
Author(s):  
Chris V. Pilcher
Keyword(s):  
Multidisciplinary Design Optimization ◽  
High Performance ◽  
Vortex Lattice ◽  
Optimization Techniques ◽  
Multidisciplinary Design ◽  
Preliminary Design ◽  
Adaptive Meshing ◽  
Analysis Methods ◽  
And Performance ◽  
Modern Optimization

A multidisciplinary design optimization (MDO) strategy for the preliminary design of a sailplane has been developed. The proposed approach applies MDO techniques and multi-fidelity analysis methods which have seen successful use in many aerospace design applications. A customized genetic algorithm (GA) was developed to control the sailplane optimization that included aerodynamics/stability, structures/weights and balance and, performance/airworthiness disciplinary analysis modules. An adaptive meshing routine was developed to allow for accurate modeling of the aero structural couplinginvolved in wing design, which included a finite element method (FEM) structural solver along with a vortex lattice aerodynamics solver. Empirical equations were used to evaluate basic sailplane performance and airworthiness requirements. This research yielded an optimum design that correlated well with an existing high performance sailplane. The results of this thesis suggest that preliminary sailplane design is a well suited application for modern optimization techniques when coupled with, multi-fidelity analysis methods.

Side wind and tank speed influence on lateral displacement of the projectile

2021 ◽  
pp. 24-29
Author(s):  
M. Sorokatiy ◽  
M. Voytovych ◽  
L. Velychko ◽  
O. Moskalova
Keyword(s):  
Mathematical Model ◽  
Wind Speed ◽  
Lateral Displacement ◽  
Longitudinal Section ◽  
Projectile Velocity ◽  
Air Density ◽  
Dimensionless Coefficient ◽  
Air Resistance ◽  
The Difference ◽  
Firing Distance

This article indicates the scope of the formula for determining the magnitude of the lateral displacement of the projectile under the action of crosswind, which is used in the compilation of firing tables. This formula is valid under the following conditions: the force of frontal air resistance to the motion of the projectile is proportional to the its velocity squared; wind speed components are much smaller than the horizontal component of projectile velocity; the projectile velocity projections on the Oy and Oz axes are much smaller than the projections on the Ox axis; the dimensionless coefficient of resistance and the magnitude of the crosswind are constant values. However, in reality, the force of frontal air resistance to the motion of the projectile is only sometimes proportional to the its velocity squared; the projectile velocity projections on the Oz axis may be are much smaller than the projections on the Ox axis and may even be greater than it; the coefficient of resistance is depends on the value of the Makh number, so it can be considered constant only when shooting at short distances. The authors propose a mathematical model for determining the magnitude of the lateral displacement of the projectile under the action of crosswinds. It is believed that the force of the crosswind on the projectile depends on the following factors: air density; the maximum area of the longitudinal section of the projectile; the difference between the value of the lateral component of the wind speed and the speed of the lateral displacement of the projectile, which is raised to a certain power. The magnitude of the values of the lateral displacement of the projectile under the action of the crosswind when shooting at short distances, determined based on the proposed mathematical model, slightly differ from the values of the lateral displacement specified in the firing tables. However, with increasing firing distance, the difference between these values is constantly increasing and the value of the lateral displacement of the projectile determined theoretically is much larger than indicated in the firing tables. In addition, in this research the influence of the tank velocity on the value of the projectile lateral displacement taking into account the action of the crosswind is studied.

A High Performance Model for Task Allocation in Distributed Computing System Using K-Means Clustering Technique

2018 ◽  
Vol 9 (3) ◽  
pp. 1-23 ◽  
Author(s):  
Harendra Kumar ◽  
Nutan Kumari Chauhan ◽  
Pradeep Kumar Yadav
Keyword(s):  
Mathematical Model ◽  
Distributed Computing ◽  
High Performance ◽  
Computing System ◽  
Performance Model ◽  
Communication Costs ◽  
Clustering Technique ◽  
Proposed Model ◽  
Two Stages ◽  
The Mathematical Model

Tasks allocation is an important step for obtaining high performance in distributed computing system (DCS). This article attempts to develop a mathematical model for allocating the tasks to the processors in order to achieve optimal cost and optimal reliability of the system. The proposed model has been divided into two stages. Stage-I, makes the ‘n' clusters of set of ‘m' tasks by using k-means clustering technique. To use the k-means clustering techniques, the inter-task communication costs have been modified in such a way that highly communicated tasks are clustered together to minimize the communication costs between tasks. Stage-II, allocates the ‘n' clusters of tasks onto ‘n' processors to minimize the system cost. To design the mathematical model, executions costs and inter tasks communication costs have been taken in the form of matrices. To test the performance of the proposed model, many examples are considered from different research papers and results of examples have compared with some existing models.

scholarly journals Molecular circuits for associative learning in single-celled organisms

2008 ◽  
Vol 6 (34) ◽  
pp. 463-469 ◽  
Author(s):  
Chrisantha T Fernando ◽  
Anthony M.L Liekens ◽  
Lewis E.H Bingle ◽  
Christian Beck ◽  
Thorsten Lenser ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Mathematical Model ◽  
Associative Learning ◽  
Experimental Evidence ◽  
Protein Kinases ◽  
Regulatory Network ◽  
Preliminary Design ◽  
Phosphorylated Protein ◽  
Alternative Approach ◽  
Gene Regulatory

We demonstrate how a single-celled organism could undertake associative learning. Although to date only one previous study has found experimental evidence for such learning, there is no reason in principle why it should not occur. We propose a gene regulatory network that is capable of associative learning between any pre-specified set of chemical signals, in a Hebbian manner, within a single cell. A mathematical model is developed, and simulations show a clear learned response. A preliminary design for implementing this model using plasmids within Escherichia coli is presented, along with an alternative approach, based on double-phosphorylated protein kinases.

Mathematical Modeling of Steppe Fires

2020 ◽  
pp. 48-62 ◽  
Author(s):  
Valeriy Afanasievich Perminov
Keyword(s):  
Mathematical Modeling ◽  
Mathematical Model ◽  
Wind Speed ◽  
Vegetation Cover ◽  
Meteorological Conditions ◽  
Condensed Phases ◽  
Pyrolysis Products ◽  
Rate Of Spread ◽  
The Mathematical Model ◽  
Steppe Fires

The chapter presents a mathematical model of the initiation and spread of the steppe fire. The mathematical model is based on the laws of mechanics of multiphase reacting media. The main physicochemical processes describing the drying, pyrolysis, and combustion of gaseous and condensed pyrolysis products are taken into account. As a result of the numerical solution, the distributions of the velocity, temperature, and concentration fields of the components of the gas and condensed phases were determined. The dependence of the rate of spread of the steppe fire on the main parameters of the state of vegetation cover and wind speed was studied. The mathematical model presented in the chapter can be used to predict the spread of steppe fires for various types of steppe vegetation and meteorological conditions, as well as for preventive measures.

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