A Simplified Turbocharged Diesel Engine Model

Author(s):  
M P Ford

A simplified model of a turbocharged marine diesel is developed which is suitable for stability studies of diesel electric generator systems. By comparison with the manufacturer's detailed thermodynamic model, the simplified model was shown to have high steady state and transient accuracy over a wide load range.

Author(s):  
Huan Tu ◽  
Hui Chen

In actual operation process of a ship, the engine-propeller-hull is an integrated system with internal coupling effects, and thus there is a close interaction between the diesel engine propulsion system operation conditions and the ship manoeuvring motions. The propulsion system can experience large power fluctuation during manoeuvring, with considerable torque increase with regard to the stabilized value in straight course. However, the diesel engine propulsion system behaviour and ship manoeuvrability are usually studied separately as they are considered to belong to different disciplines. Thus, it is difficult to reflect the actual operating characteristics of the propulsion system and ship manoeuvring motion under coupled conditions in actual operation. To investigate the interaction between the propulsion system behaviour and the manoeuvrability of a large containership, this paper proposed a multi-disciplinary ship mobility model capable of coupling the marine diesel engine model and the ship manoeuvring model. In the engine model, the mean value modelling approach was adopted to simulate the two-stroke marine diesel engine considering the fact that it can capture the performance of the engine sub-systems including scavenging receiver, exhaust gas receiver, turbocharger, etc. In the manoeuvring model, the MMG-based method was used to simulate the ship manoeuvring motion with three degrees-of-freedom. The engine model and manoeuvring model were coupled through the propeller model that transferring propeller speed and torque between the two models. The coupled model was validated against the engine shop test data and the sea trial results. By applying this coupled model, a series of simulations of turning circle manoeuvres under various scenarios were performed. The simulation results presented the dynamic response of engine internal sub-systems during turning circle manoeuvring, explained the effect of the torque limiter on engine performance and ship manoeuvring motion, and analyse the influence of different propulsion system control strategies on the ship turning circle manoeuvrability. Although the presented case study has been validated on a specific ship, most of the discussed models have a general application.


2019 ◽  
Vol 252 ◽  
pp. 05012
Author(s):  
Łukasz Grabowski ◽  
Konrad Pietrykowski ◽  
Paweł Karpiński

The analysis of the distribution of thermal energy generated during the combustion process in internal combustion engines and the estimation of individual losses are important regarding performance and efficiency. The article analyses the energy balance of the designed two-stroke opposed piston diesel engines with offset, i.e. the angle by which the crankshaft at the side of exhaust ports is ahead of the crankshaft at the side of intake ports. Based on the developed zero-dimensional engine model, a series of simulations were performed in steady-state conditions using the AVL BOOST software. The values of individual energy losses, including cooling losses, exhaust gas losses, friction losses were obtained. The influence of decreasing and increasing the offset on the performance of the tested engine was analysed.


2021 ◽  
Author(s):  
Marcin Zacharewicz ◽  
Tomasz Kniaziewicz

The paper presents the results of model and empirical tests conducted for a marine diesel engine fueled by a blend of n-butanol and diesel oil. The research were aimed at assessing the usefulness of the proprietary diesel engine model in conducting research on marine engines powered by alternative fuels to fossil fuels. The authors defined the measures of adequacy. On their basis, they assessed the adequacy of the mathematical model used. The analysis of the results of the conducted research showed that the developed mathematical model is sufficiently adequate. Therefore, both the mathematical model and the computer program based on it will be used in further work on supplying marine engines with mixtures of diesel oil and biocomponents.


2020 ◽  
Vol 3 (3) ◽  
pp. 359-372
Author(s):  
Vladimir Pelić ◽  
Tomislav Mrakovčić ◽  
Ozren Bukovac ◽  
Marko Valčić

Increasing demands on energy efficiency and environmental acceptance are being imposed on marine propulsion plants. The fulfilment of the conditions set by the MARPOL Convention, Annex VI, regarding the emissions from exhaust gases of marine diesel engines is of particular interest. This paper presents the development and validation of a zero-dimensional, single-zone diesel engine numerical model. Presented numerical model is based on the law of conservation of energy and mass and solving the resulting differential equations. The single-zone model will serve as the basis for a model where the cylinder space is divided into two or three zones during combustion. In this way, the multi-zone model will allow the modelling of nitrogen oxide emissions with satisfactory accuracy. Validation of the diesel engine model was carried out for the Wärtsilä 12V50DF 11700 kW motor designed to drive a synchronous alternator. Obtained results and deviations of certain parameters in the operation of the engine with respect to the data obtained from the measurements on the test bed, are more than satisfactory regarding complexity of the numerical model. This confirmed the usability of the model for research purposes to optimize the marine diesel engine.


2017 ◽  
Vol 23 (3) ◽  
pp. 297-309 ◽  
Author(s):  
Rakesh Mishra ◽  
Syed Mohammad Saad

Purpose Use of fossil fuels in automotive sector is one of the primary causes of greenhouse emissions. The automotive engines need to perform at their best efficiency point to limit these emissions. Most of the quality indicators in this regard are based on near steady state global operational characteristics for engines without considering local performance. In the present study, extensive numerical simulations have been carried out covering a wide range of steady state and transient operating conditions to quantify interaction of turbocharger with engines through turbo lag phenomena which may cause increased emissions during the load change conditions. Furthermore possible innovations have been explored to minimize turbo lag phenomena. The paper aims to discuss these issues. Design/methodology/approach In this paper quality indicators have been developed to quantify the performance of turbocharged diesel engine under the transient event of rapid change in fueling rate which has been rarely investigated. The rate of fueling is changed from 40 mm3/injection to 52 mm3/injection at 1,000 rpm engine speed which corresponds to normal operating condition. To improve quality of transient response, torque assistance method and reduction of inertia of compressor wheel have been used. Parametric study has been undertaken to analyze the quality indicators such as outlet pressure of the compressor and the compressor speed. The turbo lag is quantified to obtain the close to optimal transient response of turbocharged diesel engine. Findings It has been shown that, with torque assist the transient response of the internal combustion engine is significantly improved. On the other hand, marginal improvement in transient response is observed by the reduction in inertia of the compressor wheel. Research limitations/implications The findings indicate that turbo lag can be minimized by providing torque assistance by active and passive means. Practical implications The developed methods can be used in practice for efficient operation of vehicles. Social implications The work carried out in the paper provides a way to minimize harmful emissions. Originality/value The quality indicators developed provide a quantitative measure of turbo lag phenomena and address the above mentioned problems.


Author(s):  
Kamal Kharroubi ◽  
Oğuz Salim Söğüt

In this article, a mathematical replica of the propulsive installation of a large container ship is presented. The ship propulsion is accomplished by a large two-stroke marine diesel engine driving a marine propeller. The main new idea introduced by this research consists in using the Subsystem-Enabling feature available in the MATLAB Simulink® environment to control the execution of the working sequences of the main propulsion two-stroke diesel engine. The benefits brought by this model implementation approach are its simplicity and its applicability to all the blocks of the diesel engine model, these blocks can be created to represent one engine working sequence and then duplicated to represent the remaining engine sequences, and finally, the blocks related to each sequence can be grouped in subsystems and controlled by a single subsystem monitoring the engine events according to the value of the crankshaft angle; consequently, the overall Simulink model building and execution processes are much faster. The results generated by the simulation using the Simulink model of this diesel ship propulsion plant show that, for the production of acceptable results, only a small portion of the input data of the model needs to be exactly provided by the manufacturers of the components of the propulsion plant, whereas the rest of the data can be given reasonable initial values and adjusted during the model’s fine-tuning process. Finally, it is worth noting that the considerable amount of simulator-input-data available in this article can be used in any other simulation work to develop an identical simulator to the simulator of this article or to build a different one from scratch.


Sign in / Sign up

Export Citation Format

Share Document