The Variable Outlet Turbine Concept for Turbochargers

2014 ◽  
Vol 136 (12) ◽  
Author(s):  
Elias Chebli ◽  
Michael Casey ◽  
Ricardo Martinez-Botas ◽  
Siegfried Sumser ◽  
Markus Müller ◽  
...  
Keyword(s):  
Fuel Consumption ◽  
Engine Performance ◽  
Engine Fuel ◽  
Performance Measurements ◽  
Flow Variability ◽  
Variable Turbine Geometry ◽  
Turbine Efficiency ◽  
Computational Fluid Dynamics Simulations ◽  
Dynamics Simulations ◽  
Flow Cross

A variable geometry concept for advanced turbocharger (TC) systems is presented. The variability of the device is based on outlet area changes as opposed to the more common systems that are based on inlet turbine geometry changes. In addition to the conventional variable turbine geometry (VTG), the new variable turbine type is termed variable outlet turbine (VOT). The flow variability is achieved by variation of the flow cross section at the turbine outlet using an axial displacement of a sliding sleeve over the exducer and provides a simple solution for flow variability. In order to predict the aerodynamic performance and to analyze the loss mechanisms of this new turbine, the flow field of the VOT is calculated by means of steady state 3D-CFD (computational fluid dynamics) simulations. The VOT design is optimized by finding a good balance between clearance and outlet losses. Furthermore, experimental results of the VOT are presented and compared to a turbine equipped with a waste gate (WG) that demonstrates an efficiency advantage of 5%. Additionally, engine performance measurements were carried out to investigate the influence of the VOT on fuel consumption and to asses the functionality of the new pneumatic actuating system. The VOT engine tests show also performance advantage in comparison to a WG turbine especially toward high engine loads. It is found that the use of the VOT at this condition shows a turbine efficiency advantage of 6% related to a reduction in engine fuel consumption of 1.4%. The behavior at part load is neutral and the peak turbine efficiency of the VOT is comparable with a fix turbine geometry.

Innovative Variable Turbine Concept for Turbochargers

2011 ◽  
Author(s):  
Elias Chebli ◽  
Michael Casey ◽  
Markus Mu¨ller ◽  
Siegfried Sumser ◽  
Gernot Hertweck ◽  
...  
Keyword(s):  
Aerodynamic Performance ◽  
Cfd Simulations ◽  
Flow Variability ◽  
Variable Turbine Geometry ◽  
Turbine Efficiency ◽  
New Concepts ◽  
Specific Speed ◽  
Turbine Impeller ◽  
Flow Cross ◽  
Wide Operating

New concepts for the optimisation of supercharging systems have been analysed to improve fuel consumption, emissions and transient diesel engine response. In addition to the conventional VTG (Variable Turbine Geometry) where the variability takes place upstream of the turbine impeller, a new innovative variable turbine geometry called VOT (Variable Outlet Turbine) is investigated in this paper where the variability takes place at impeller exit. The flow variability is achieved by variation of the flow cross-section at the turbine outlet using an axial displacement of a sliding sleeve over the exducer and provides a simple solution for flow variability. The flow field of the VOT is calculated by means of steady state 3D-CFD simulations to predict the aerodynamic performance as well as to analyse the loss mechanisms. The VOT design is optimised by finding a good balance between clearance and outlet losses to improve the turbine efficiency. Furthermore, experimental results of the VOT are presented and compared to a turbine equipped with a waste gate (WG) that verify the efficiency advantage of the VOT. In general, it is found that the use of the VOT at high specific speed is important to reduce the outlet losses and to improve the turbine efficiency over a wide operating range.

scholarly journals Neural Nonlinear Autoregressive Model with Exogenous Input (NARX) for Turboshaft Aeroengine Fuel Control Unit Model

Aerospace ◽  
2021 ◽  
Vol 8 (8) ◽  
pp. 206
Author(s):  
Maria Grazia De Giorgi ◽  
Luciano Strafella ◽  
Antonio Ficarella
Keyword(s):  
Neural Networks ◽  
Control System ◽  
Fuel Consumption ◽  
Control Method ◽  
Engine Performance ◽  
Control Unit ◽  
Specific Fuel Consumption ◽  
Engine Fuel ◽  
State Variables ◽  
Nonlinear Autoregressive

One of the most important parts of a turboshaft engine, which has a direct impact on the performance of the engine and, as a result, on the performance of the propulsion system, is the engine fuel control system. The traditional engine control system is a sensor-based control method, which uses measurable parameters to control engine performance. In this context, engine component degradation leads to a change in the relationship between the measurable parameters and the engine performance parameters, and thus an increase of control errors. In this work, a nonlinear model predictive control method for turboshaft direct fuel control is implemented to improve engine response ability also in presence of degraded conditions. The control objective of the proposed model is the prediction of the specific fuel consumption directly instead of the measurable parameters. In this way is possible decentralize controller functions and realize an intelligent engine with the development of a distributed control system. Artificial Neural Networks (ANN) are widely used as data-driven models for modelling of complex systems such as aeroengine performance. In this paper, two Nonlinear Autoregressive Neural Networks have been trained to predict the specific fuel consumption for several transient flight maneuvers. The data used for the ANN predictions have been estimated through the Gas Turbine Simulation Program. In particular the first ANN predicts the state variables based on flight conditions and the second one predicts the performance parameter based on the previous predicted variables. The results show a good approximation of the studied variables also in degraded conditions.

Investigation of a In-Line Oil-Cleaning Device for 4-Stroke Locomotive Diesel Engine Use

2001 ◽  
Author(s):  
Fan Su ◽  
Malcolm Payne ◽  
Manuel Vasquez ◽  
Aref Taghizadeh
Keyword(s):  
Fuel Consumption ◽  
Operating Time ◽  
Combustion Process ◽  
Engine Performance ◽  
Engine Oil ◽  
Engine Fuel ◽  
Emission Data ◽  
Medium Speed ◽  
Cleaning Device ◽  
Test Engine

Abstract Tests have been performed on a single-cylinder medium-speed diesel research engine (SCRE-251) to investigate the possibility of using an in-line oil-cleaning device (IOD) on diesel locomotive engines for improving engine performance and exhaust emissions. The engine was operated at full load for both the baseline and with IOD test. Engine fuel consumption and emission data were obtained at different engine operating time. The effects of the device on engine combustion process were determined by analyzing recorded engine cylinder pressure data. Oil samples were taken during the test to monitor changes in oil properties. The engine test results showed that the device reduced engine fuel consumption by up to 2% of the baseline results. Average CO and smoke of the device were lower and average NOx of the device was higher than that of baseline. The trends of changes of fuel consumption and emissions are consistent with Taylor’s [1] investigations. Engine oil analysis indicated that the viscosity, TAN and TBN data of the IOD test changed slightly with increasing oil-aging time.

Effects of Humidity and Ambient Temperature on Engine Performance of Lean Burn Natural Gas Engines

2006 ◽  
Author(s):  
Andreas Wimmer ◽  
Eduard Schnessl
Keyword(s):  
Natural Gas ◽  
Fuel Consumption ◽  
Engine Performance ◽  
Optimal Operation ◽  
Nox Emission ◽  
Engine Fuel ◽  
Ambient Conditions ◽  
Lean Burn ◽  
Combustion Duration ◽  
Burn Rate

High demands are placed on large gas engines in the areas of performance, fuel consumption and emissions. In order to meet all these demands, it is necessary to operate the engine in its optimal range. At high engine loads the optimal operation range becomes narrower as the engine comes closer to the knocking or to the misfire limit. The ambient conditions are of increasing importance in this range of operation. Variations in humidity influence the engine’s burn rate characteristics. An increase in humidity reduces the burn rate and increases the combustion duration. This increase in combustion duration has the same effect as retarding the time of ignition. Thus the thermal efficiency is reduced. Additionally, the engine is more likely to misfire as humidity increases. The cylinder temperature affects the engine fuel efficiency, knocking, exhaust gas temperature and particularly NOx emission. An increase in manifold air temperature results in higher NOx emission, heat transfer and knocking tendency. To avoid knocking, the time of ignition must be retarded resulting in lower engine efficiency. In this paper the effects of changes in humidity and temperature of the intake air on engine performance were examined in a lean burn pre-chamber natural gas engine. Tests on a single cylinder research engine were carried out. Effects on knocking and misfire limit, NOx emissions and fuel consumption were investigated depending on engine load. The interpretation of the results was supported by an extended analysis of losses.

scholarly journals Determination of the isentropic turbine efficiency due to adiabatic measurements and the validation of the conditions via a new criterion

2016 ◽  
Vol 232 (24) ◽  
pp. 4485-4494 ◽  
Author(s):  
R Zimmermann ◽  
R Baar ◽  
C Biet
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Boundary Conditions ◽  
Measuring Equipment ◽  
Turbine Efficiency ◽  
Computational Fluid Dynamics Simulations ◽  
Dynamics Simulations ◽  
New Criterion

The determination of the isentropic turbine efficiency under adiabatic and SAE boundary conditions is studied in this paper. The study is structured into two parts. The first part describes the possibility of measuring the isentropic turbine efficiency directly. Normally this is not possible in measurements conducted following the SAE J922 guidelines. Therefore, the experiments have been carried out under adiabatic conditions, and combined with improved measuring equipment. The results were compared with adiabatic computational fluid dynamics simulations of this turbocharger. In the second part, a new criterion is defined in order to evaluate the quality of the adiabatic measurements and compare them with standard measurements. The investigation has been carried out with multiple turbochargers ranging from very small to medium passenger car size turbochargers. In the end, a possible application for the criterion is given.

Production of Biodiesel From Used Mustard Oil and Its Performance Analysis in Internal Combustion Engine

2010 ◽  
Vol 132 (3) ◽  
Author(s):  
Baljinder Singh ◽  
Jagdeep Kaur ◽  
Kashmir Singh
Keyword(s):  
Fuel Consumption ◽  
Fossil Fuel ◽  
Combustion Engine ◽  
Indian Mustard ◽  
Engine Performance ◽  
Internal Combustion ◽  
Mustard Oil ◽  
Engine Fuel ◽  
Good Efficiency ◽  
Crude Oil Prices

Decline in fossil fuel resources along with high crude oil prices generated attention toward the development of fuel from alternate sources. Such fuel should be economically attractive and performance competent in order to replace the fossil fuel. Mustard oil from Indian mustard, Brassica campestris, is commonly used for cooking in Indian households and restaurants. Cooking produces spent mustard oil waste, which is generally drained as garbage. We explored the possibility of using such spent mustard oil for making biodiesel. Transesterification of spent oil was carried out using methanol and sulfuric acid (95%) as catalysts followed by bubble washing. Clear biodiesel was obtained from esterified oil after five bubble washings. Methyl ester formations were calculated by measuring its density at 15°C and viscosity at 40°C and were found to be 89 g/cm3 and 4.83 mm2/s, respectively. Studies on engine performance were conducted using a Prony brake internal combustion (IC) diesel engine using various blending ratios of biodiesel with commercial diesel. The fuel blends were evaluated for parameters such as speed of engine, fuel consumption, and torque against pure diesel. Brake power, specific fuel consumption, and thermal efficiency were also measured. The results indicate that dual fuel with a blend of 8% biodiesel yielded good efficiency in the IC-diesel engines without the need for making any modifications in the engine.

scholarly journals Diesel engine performance modelling using neural networks

2005 ◽  
Author(s):  
◽  
Mark Steve Rawlins
Keyword(s):  
Neural Network ◽  
Neural Networks ◽  
Diesel Engine ◽  
Fuel Consumption ◽  
Diesel Engines ◽  
Engine Performance ◽  
Specific Fuel Consumption ◽  
Engine Fuel ◽  
Modular Network ◽  
Feed Forward

The aim of this study is to develop, using neural networks, a model to aid the performance monitoring of operational diesel engines in industrial settings. Feed-forward and modular neural network-based models are created for the prediction of the specific fuel consumption on any normally aspirated direct injection four-stroke diesel engine. The predictive capability of each model is compared to that of a published quadratic method. Since engine performance maps are difficult and time consuming to develop, there is a general scarcity of these maps, thereby limiting the effectiveness of any engine monitoring program that aims to manage the fuel consumption of an operational engine. Current methods applied for engine consumption prediction are either too complex or fail to account for specific engine characteristics that could make engine fuel consumption monitoring simple and general in application. This study addresses these issues by providing a neural network-based predictive model that requires two measured operational parameters: the engine speed and torque, and five known engine parameters. The five parameters are: rated power, rated and minimum specific fuel consumption bore and stroke. The neural networks are trained using the performance maps of eight commercially available diesel engines, with one entire map being held out of sample for assessment of model generalisation performance and application validation. The model inputs are defined using the domain expertise approach to neural network input specification. This approach requires a thorough review of the operational and design parameters affecting engine fuel consumption performance and the development of specific parameters that both scale and normalize engine performance for comparative purposes. Network architecture and learning rate parameters are optimized using a genetic algorithm-based global search method together with a locally adaptive learning algorithm for weight optimization. Network training errors are statistically verified and the neural network test responses are validation tested using both white and black box validation principles. The validation tests are constructed to enable assessment of the confidence that can be associated with the model for its intended purpose. Comparison of the modular network with the feed-forward network indicates that they learn the underlying function differently, with the modular network displaying improved generalisation on the test data set. Both networks demonstrate improved predictive performance over the published quadratic method. The modular network is the only model accepted as verified and validated for application implementation. The significance of this work is that fuel consumption monitoring can be effectively applied to operational diesel engines using a neural network-based model, the consequence of which is improved long term energy efficiency. Further, a methodology is demonstrated for the development and validation testing of modular neural networks for diesel engine performance prediction.

scholarly journals Uji Eksperimental Konsumsi Bahan Bakar Mesin Berbahan Bakar Biodiesel Minyak Kelapa Hasil Metode Kering

2011 ◽  
Vol 1 (2) ◽  
Author(s):  
Yesung Allo Padang
Keyword(s):  
Diesel Engine ◽  
Energy Conversion ◽  
Fuel Consumption ◽  
Engine Speed ◽  
Experimental Testing ◽  
Engine Performance ◽  
Coconut Oil ◽  
Diesel Oil ◽  
Engine Fuel ◽  
Effective Power

Experimental testing using coconut oil produced by dry method on engine has been conducted in the Laboratory of Energy Conversion, Mechanical Engineering, Mataram University. The purpose was to evaluate the effect of using this coconut oil on the engine performance. The oil was mixed with diesel oil in order to obtain biodiesel. There were four combinations of ratio diesel oil to coconut oil; namely 100% : 0% (mkp0%), 90%:10% (mkp10%), 80%:20% (mkp20%) and 70%:30% (mkp30%.). Mitsubishi L300 diesel engine was used in this experiment by variating engine speed 1000 rpm, 1050 rpm and 1100 rpm with torgue load at 1 kg. At engine speed of 1200 rpm the loads were varied as 1 kg, 1.5 kg and 2 kg. The result shows that by increasing the number of coconut oil in the mixture will reduce engine fuel consumption. Fuel consumption of the mixture will be better compare to the fuel consumption of pure diesel oil. Specific fuel consumption efective (SFCe) of coconut oil-diesel mixture at mkp 10%, 20% and 30% are lower than of pure diesel oil. The reduced SFCe are 1.45 %, 1.71% and 3.57 % at effective power 0.838 PS, 1.98%, 4.31% and 4.31% at effective power 1.257 PS and 1.22%, 3.92% and 7.12% at effective power 1.676 PS. By varying the engine speed, the result also shows that SFCe of the mixture is also lower than SFCe of pure diesel oil.

Design and Application of a Multi-Disciplinary Pre-Design Process for Novel Engine Concepts

2018 ◽  
Author(s):  
S. Reitenbach ◽  
A. Krumme ◽  
T. Behrendt ◽  
M. Schnös ◽  
T. Schmidt ◽  
...  
Keyword(s):  
Gas Turbine ◽  
Fuel Consumption ◽  
Co2 Emissions ◽  
Design Process ◽  
Data Model ◽  
Gas Turbines ◽  
Engine Performance ◽  
Preliminary Design ◽  
Engine Fuel ◽  
Engine Components

Central targets for jet engine research activities comprise the evaluation of improved engine components and the assessment of novel engine concepts for enhanced overall engine performance in order to reduce the fuel consumption and emissions of future aircraft. Since CO2 emissions are directly related to engine fuel burn, a reduction in fuel consumption leads to lower CO2 emissions. Therefore improvements in engine technologies are still significant and a multi-disciplinary pre-design approach is essential in order to address all requirements and constraints associated with different engine concepts. Furthermore, an increase in effectiveness of the preliminary design process helps reduce the immense costs of the overall engine development. Within the DLR project PEGASUS (Preliminary Gas Turbine Assessment and Sizing) a multi-disciplinary pre-design and assessment competence of the DLR regarding aero engines and gas turbines was established. The application of modern preliminary design methods allows for the construction and evaluation of innovative next generation engine concepts. The purpose of this paper is to present the developed multi-disciplinary pre-design process and its application to three aero engine models. First, a state of the art twin spool mixed flow turbofan engine model is created for validation purposes. The second and third engine models investigated comprise future engine concepts: a Counter Rotating Open Rotor and an Ultra High Bypass Turbofan. The turbofan used for validation is based on publicly available reference data from manufacturing and emission certification. At first the identified interfaces and constraints of the entire pre-design process are presented. An important factor of complexity in this highly iterative procedure is the intricate data flow, as well as the extensive amount of data transferred between all involved disciplines and among the different fidelity levels applied within the smoothly connected design phases. To cope with the inherent complexity data modeling techniques have been applied to explicitly determine the required data structures of those complex systems. The resulting data model characterizing the components of a gas turbine and their relationships in the design process is presented in detail. Based on the established data model the entire engine pre-design process is presented. Starting with the definition of a flight mission scenario and the resulting top level engine requirements thermodynamic engine performance models are developed. By means of these thermodynamic models, a detailed engine component pre-design is conducted. The aerodynamic and structural design of the engine components are executed using a stepwise increase in level of detail and are continuously evaluated in the context of the overall engine system.

Application of Box-Behnken Analysis on the Optimisation of Air Intake System for a Naturally Aspirated Engine

2020 ◽  
Vol 17 (2) ◽  
pp. 8029-8042
Author(s):  
N.S. Mustafa ◽  
N.H.A. Ngadiman ◽  
M.A. Abas ◽  
M.Y. Noordin
Keyword(s):  
Fuel Consumption ◽  
Fuel Efficiency ◽  
Engine Performance ◽  
Fuel Price ◽  
Design Expert ◽  
Intake System ◽  
Analysis Technique ◽  
System Components ◽  
Air Intake ◽  
High Influence

Fuel price crisis has caused people to demand a car that is having a low fuel consumption without compromising the engine performance. Designing a naturally aspirated engine which can enhance engine performance and fuel efficiency requires optimisation processes on air intake system components. Hence, this study intends to carry out the optimisation process on the air intake system and airbox geometry. The parameters that have high influence on the design of an airbox geometry was determined by using AVL Boost software which simulated the automobile engine. The optimisation of the parameters was done by using Design Expert which adopted the Box-Behnken analysis technique. The result that was obtained from the study are optimised diameter of inlet/snorkel, volume of airbox, diameter of throttle body and length of intake runner are 81.07 mm, 1.04 L, 44.63 mm and 425 mm, respectively. By using these parameters values, the maximum engine performance and minimum fuel consumption are 93.3732 Nm and 21.3695×10-4 kg/s, respectively. This study has fully accomplished its aim to determine the significant parameters that influenced the performance of airbox and optimised the parameters so that a high engine performance and fuel efficiency can be produced. The success of this study can contribute to a better design of an airbox.

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