Planetary gear systems are widely used in wind power systems because of the advantages of compact design, large carrying capacity, and high transmission efficiency. Despite these advantages, the several conditions under which such gears are typically used may lead to failure. Tooth pitting is one of the frequently encountered failure modes. The damage of teeth (as tooth pitting) is modeled for a wind turbine drive train. The drive train has got a three-stage gearbox that contains two high-speed parallel gear stages and a low-speed planetary gear stage. The proposed dynamic model of a wind turbine also includes a rotor and an electric generator. The model consists of 10 bodies and has got 11 degrees of freedom. The aerodynamic and generator torques are applied as external loads. The influence of tooth pitting on the gear mesh stiffness is scrutinized. Healthy drive train dynamic response and response of drive train containing tooth pitting are compared. The obtained results give an useful information about health monitoring of wind turbine drive train.
Machines. Technologies. Materials.
Vol. 9 (2015), Issue 3
Table of Contents
SCHEMATISATION THE STUDY PROCESS OF MULTIBODY ROAD VEHICLE MODELS DESCRIBING RIDE COMFORT – PART I. METHODS OF CLASSICAL MECHANICSpg(s) 3-6
The objective of this study is investigation possibilities to obtain main parameters of road vehicle ride comfort using formal matrix approach. The automobile is modeled as a dynamic system made of masses interconnected by springs and dampers with linear characteristics. The procedure is applied about four to eight wheel models. The engine, transmission, passengers and loads are presented like a simple masses suspended on a single springs. In the paper are written the main principles of calculation procedure for formal modeling typical vehicle dynamic system.
The article presents a modern approach for studying the combustion process in the DI Diesel engines developed for passenger car. The mixing controlled combustion model has been chosen for estimation the rate of heat released in the combustion chamber as well as the Arrhenius equation was used for ignition delay determination. The injection rate was calculated by means of constant injection pressure as well. Zero dimensional thermodynamic models have been used for estimation the in-cylinder parameters. All of the models were implemented as a computational code in Matlab. Finally, in-cylinder parameters variation such as pressure, temperature, rate of heat released etc., were studied at two engine operating points.
The publication describes the properties of isopropyl alcohol and is exploring the possibility of its use as an additive to diesel fuel. Experimental results from operation of the diesel engine with 15% isopropyl alcohol are shown. The advantages of using a 15%- mixture of isopropyl alcohol and standard diesel fuel are presented here. The main physicochemical parameters of the isopropyl alcohol are also shown as well as the specification of the used diesel fuel. The specifications of the test engine are given here in detail. The experimental results are presented in both tabular and graphical form. The main economical parameters are show as a function of the load characteristics. Graphical functions proving the smoke density reduction as a function of the load characteristics, air-fuel ratio and multi- parameter characteristics are also presented. The smoke reduction is observed in exhaust gas of the diesel engine.
This paper presents the results of an analytical study for optimisation of the full-load operation of a compression ignition internal combustion engine with common rail fuel system. The model is made with the aid of the software simulation package Advanced Simulation Tools by AVL List GmbH. An existing engine is used as a prototype of the model – a PSA-manufactured DW10BTED4. The received characteristics from the performance are compared with the manufacturer data. A possible range of model improvements are also presented in the paper.
The standardization is a specific activity, which obeys principles, has its own methods, can take different forms and has objects with diverse character. The standardization activity includes the developing, approving, issuing and the application of the standards processes. In this article have been examined the standardization’s main formulations and methods at international, regional, national and company level. Therefore the generally acknowledged, basic principles and rules for work of the standardization are being respected. The standards are being developed and published in the society interest and represent mean of information and mutual understanding between partners.
The lack of adequate consumer culture hinders communication between businesses and consumers, which has negative consequences for both sides. Nowadays most people have fairly good overall consumer culture, and it continues to evolve spontaneously along with the development of the market.
INVESTIGATION OF THE WEAR PATTERNS OF CENTRIFUGAL PUMP 8 GR-8 PARTS IN THE CONDITIONS OF “KAZAKHMYS” CO. ORE-DRESSING PLANTpg(s) 46-49
The paper considers centrifugal pumps 8 Gr-8, component of the hydro-transport of the ore-dressing operation line, which pumps abrasive hydro-mixtures (pulp). The pumps working conditions are described and the results from wear measurement of the impeller, wear plate and housing are shown for different operation times. The wear patterns of the examined parts are determined and the causes for their intensive wear and the methods of its reduction are identified.
High-speed crafts’ reliability as well as its passenger’s comfort and safety are closely related to the craft’s dynamics on sea waves. The resultant dynamics are governed by the quality of the motion control system and its capacity for quality kinematic data acquisition. Herein, we propose a novel method for determining accelerometers’ mounting positions within a hydrofoil ship. This method eliminates interference from the output of accelerometers and provides the capability of determining the amplification coefficients of the second derivative with respect to the height of the ship’s motion.
The paper deals with the analysis of the factors and aspects covered by the Diesel Engine Reliability Theory and relevant for the discussion of engine reliability. The paper suggests and examines indicators for the assessment of engine reliability, and quantitative function for the evaluation of engine technical condition. The integrated effect of mountainous dessert on automotive engines is also examined although it has received little research attention so far, whereas findings of quantitative criteria analysis intended for reliability assessment under difficult conditions have not been publicly reported as they have been accomplished by manufacturers of military vehicles.
Engine operating conditions refer to the manner of engine use, intensity of engine operation, different types of engine loads and their sequence, as well as culture and qualification of drivers, servicemen and maintenance personnel, provision of repair and diagnostics equipment, etc.
Research of the case under consideration has been accomplished in mountainous desert of Afghanistan showing complicated climatic conditions. For the purpose of collecting precise and accurate data, vehicles used by the Provincial Reconstruction Team situated in Ghor province (Afghanistan) were selected for the research. Their operation course, failures, and repairs can be tracked and captured more precisely than those of civilians as their data are recorded in data logs.
The article introduces a model which might be used for supplying spare parts of ground forces technical equipment to the Army of the Czech Republic. When designing inventory management, an Economic Order Quantity (EOQ) model is applied. It is a classical model used to determine stock order quantity. When setting the model, stock classification based on the ABC method and the EW matrix is made.
Following the stock classification, for the Army of the Czech Republic we would suggest determining a signal stock level which is the same as for the Q-model of a stock management system. In this model used to optimize the stock we apply a dynamic model with absolutely determined stock movement, a dynamic multiproduct model where purchase cost is constant, and a dynamic model completed by a temporary unsatisfied demand. The important aspects which should be taken into consideration when setting an inventory model are stock purchase cost, storage costs, stock holding cost, or the cost which arise due to a short supply.
The current paper will present the methods, ways and concrete schemes for retrofit of ships main engine remote control (RC) systems. The drawing solutions from realized projects will be discussed for different engines. Analysis for the projects is done. Modern remote control systems of ships diesel engines are mentioned in this paper.
The nature of blended learning is expressed through dynamic educational process streaming towards perfect match of teaching and technology. That alone represents a blended learning strength for both, academic and business world. In higher education blended learning has been not a new term, but has intensively attached the importance owing to rapid development of available digital and social media that have been utilised for adequate learning environments. This paper identifies core issues and points to the challenges of this delivery mechanism in higher educational context. Some experience in the development of engineering graphics blended course is presented along with few directions for future course redesign and research.
SCHEMATISATION THE STUDY PROCESS OF MULTIBODY ROAD VEHICLE MODELS DESCRIBING RIDE COMFORT – PART II. METHODS OF MATRIX MECHANICSpg(s) 7-25
The objective of this study is investigation possibilities to obtain main parameters of road vehicle ride comfort using formal matrix approach. The automobile is modeled as a dynamic system consist masses interconnected by springs and dampers with linear characteristics. The procedure is applied about four to eight wheel models. The engine, transmission, passengers and loads are presented like a simple masses suspended on a single springs. In the paper are written the main principles of calculation procedure for formal modeling typical vehicle dynamic system.