Impact of Measurement Uncertainty in the Characteristic Maps of a Turbocharger on Engine Performance

2013 ◽  
Vol 136 (2) ◽  
Author(s):  
Holger Mai ◽  
Mathias Vogt ◽  
Roland Baar ◽  
Andreas Kinski
Keyword(s):  
Measurement Uncertainty ◽  
Process Simulation ◽  
Combustion Engine ◽  
Engine Performance ◽  
Engine Emissions ◽  
Engine Operation ◽  
Power Simulation ◽  
Systematic Uncertainties ◽  
Measurement Results ◽  
The Impact

The main goal of current engine development is to increase power density and efficiency and to minimize engine emissions. The idea is to obtain the desired power output with a highly charged combustion engine in combination with exhaust gas turbocharging and a very small engine displacement, which is known as downsizing. The selection of a turbocharger is based on the maps of the turbine and compressor, which are usually measured on a test bench. They also provide important boundary conditions on the engine process simulation of a supercharged engine with this turbocharger. In general, a very accurate measurement of the characteristic maps is desired to ensure the best possible matching. However, random and systematic errors have an impact on the measurement results. In order to assess the quality of the measured and calculated values, it is necessary to determine the uncertainties of the measurement variables as accurately as possible; particularly, the error propagation in calculating the efficiencies. The uncertainties are based on a systematic uncertainty component of the sensor and the confidence interval. In this way, the measurement uncertainty is estimated by linear and geometric combination of the calculated random and systematic uncertainties. After that, the respective uncertainty contributions and the identification of the relevant parameters that influence the resulting measurement uncertainty are evaluated. Knowing the measurement uncertainties of the characteristic maps of a turbocharger, the influence on engine operation will be determined with a one-dimensional engine process simulation model. Consequently, the determined measurement uncertainty will be applied as a deviation on the efficiencies and will be investigated in a GT POWER simulation. The impact of the measurement uncertainty on the engine performance is shown on the basis of load steps.

Impact of Measurement Uncertainty in the Characteristic Maps of a Turbocharger on Engine Performance

2013 ◽  
Author(s):  
Holger Mai ◽  
Mathias Vogt ◽  
Roland Baar ◽  
Andreas Kinski
Keyword(s):  
Measurement Uncertainty ◽  
Process Simulation ◽  
Combustion Engine ◽  
Engine Performance ◽  
Engine Emissions ◽  
Engine Operation ◽  
Power Simulation ◽  
Systematic Uncertainties ◽  
Measurement Results ◽  
The Impact

The main goal of current engine development is to increase power density and efficiency and to minimize engine emissions. The idea is to obtain the desired power output with a highly charged combustion engine in combination with exhaust gas turbocharging and a very small engine displacement, so-called downsizing. The selection of a turbocharger is based on the maps of the turbine and compressor, which are usually measured on a test bench. They also provide important boundary conditions on the engine process simulation of a supercharged engine with this turbocharger. In general, a very accurate measurement of the characteristic maps is desired to ensure the best possible matching. However, random and systematic errors have an impact on the measurement results. In order to assess the quality of the measured and calculated values, it is necessary to determine the uncertainties of the measurement variables as accurately as possible, particularly the error propagation in calculating the efficiencies. The uncertainties are based on a systematic uncertainty component of the sensor and the confidence interval. In this way the measurement uncertainty is estimated by linear and geometric combination of the calculated random and systematic uncertainties. After that, the respective uncertainty contributions and the identification of the relevant parameters that influence the resulting measurement uncertainty are evaluated. Knowing the measurement uncertainties of the characteristic maps of a turbocharger, the influence on engine operation will be determined with a one-dimensional engine process simulation model. Consequently, the determined measurement uncertainty will be applied as a deviation on the efficiencies and will be investigated in a GT POWER simulation. The impact of the measurement uncertainty on the engine performance is shown on the basis of load steps.

Parametric Study on Ported Shroud Locations and Geometries for a Turbocharger Compressor

2019 ◽  
Author(s):  
Suheab Thamizullah ◽  
Abdul Nassar ◽  
Antonio Davis ◽  
Gaurav Giri ◽  
Leonid Moroz
Keyword(s):  
Centrifugal Compressor ◽  
Combustion Engine ◽  
Engine Performance ◽  
Operating Conditions ◽  
Entire Study ◽  
Operating Condition ◽  
Baseline Design ◽  
Operating Range ◽  
Ported Shroud ◽  
The Impact

Abstract Turbochargers are commonly used in automotive engines to increase the internal combustion engine performance during off-design operating conditions. When used, the widest operating range for the turbocharger is desired, which is limited on the compressor side by the choke condition and the surge phenomenon. The ported shroud technology is used to extend the operable working range of the compressor, by permitting flow disturbances that block the blade passage to escape and stream back through the shroud cavity to the compressor inlet. The impact of this technology, on a speed-line, at near optimal operating condition, near choke operating condition and near surge operating condition is investigated. The ported shroud (PS) self-recirculating casing treatment is widely used to delay the onset of surge by enhancing the aerodynamic stability of the turbocharger compressor. While the ported shroud design delays surge, it usually comes with a small penalty in efficiency. This research involves designing a single-stage centrifugal compressor for the given specifications, considering the application of an automotive turbocharger. The ported shroud was then introduced in the centrifugal compressor. The performance characteristics were obtained, both at the design and at off-design conditions, both with and without the ported shroud. The performance was compared at various off-design operating speed lines. The entire study, from designing the compressor to optimizing the ported shroud configuration, was performed using the commercial AxSTREAM® software platform. Parametric studies were performed to study the effect of ported shroud axial location along the blade axial length on the operating range and performance. The baseline design, without the ported shroud (P0), and the final geometry with it for all PS inlet axial locations (P1 to P5) were analysed using a commercial CFD package and the results were compared with those from the streamline solver.

Homogeneous Charge Compression Ignition Operation With Natural Gas: Fuel Composition Implications

2003 ◽  
Vol 125 (3) ◽  
pp. 837-844 ◽  
Author(s):  
J. Hiltner ◽  
R. Agama ◽  
F. Mauss ◽  
B. Johansson ◽  
M. Christensen
Keyword(s):  
Natural Gas ◽  
Compression Ratio ◽  
Homogeneous Charge Compression Ignition ◽  
Engine Performance ◽  
Fuel Composition ◽  
Primary Concern ◽  
Compression Ignition ◽  
Engine Operation ◽  
The Impact ◽  
Homogeneous Charge

Homogeneous charge compression ignition (HCCI) is a potentially attractive operating mode for stationary natural gas engines. Increasing demand for efficient, clean burning engines for electrical power generation provides an opportunity to utilize HCCI combustion if several inherent difficulties can be overcome. Fuel composition, particularly the higher hydrocarbon content (ethane, propane, and butane) of the fuel is of primary concern. Fuel composition influences HCCI operation both in terms of design, via compression ratio and initial charge temperature, and in terms of engine control. It has been demonstrated that greater concentrations of higher hydrocarbons tend to lower the ignition temperature of the mixture significantly. The purpose of this paper is to demonstrate, through simulation, the effect of fuel composition on combustion in HCCI engines. Engine performance over a range of fuels from pure methane to more typical natural gas blends is investigated. This includes both the impact of various fuels and the sensitivity of engine operation for any given fuel. Results are presented at a fixed equivalence ratio, compression ratio, and engine speed to isolate the effect of fuel composition. Conclusions are drawn as to how the difficulties arising from gas composition variations may affect the future marketability of these engines.

Evaluating Gas Turbine Performance Using Machine-Generated Data: Quantifying Degradation and Impacts of Compressor Washing

2016 ◽  
Vol 138 (12) ◽  
Author(s):  
Uyioghosa Igie ◽  
Pablo Diez-Gonzalez ◽  
Antoine Giraud ◽  
Orlando Minervino
Keyword(s):  
Gas Turbine ◽  
Measurement Data ◽  
Engine Performance ◽  
Large Data ◽  
Simulation Software ◽  
Engine Operation ◽  
Compressor Inlet ◽  
Data Points ◽  
Global And Local ◽  
The Impact

Gas turbine (GT) operators are often met with the challenge of utilizing and making meaning of the vast measurement data collected from machine sensors during operation. This can easily be about 576 × 106 data points of gas path measurements for one machine in a base load operation in a year, if the width of the data is 20 columns of measured and calculated parameters. This study focuses on the utilization of large data in the context of quantifying the degradation that is mostly related to compressor fouling, in addition to investigations on the impact of offline and online compressor washing. To achieve this, four GT engines operating for about 3.5 years with 51 offline washes and 1184 occasions of online washes were examined. This investigation includes different wash frequencies, liquid concentrations, and one engine operation without online washing (only offline). This study has involved correcting measurement data not only just with compressor inlet temperatures (CITs) and pressures but also with relative humidity (RH). turbomatch, an in-house GT performance simulation software has been implemented to obtain nondimensional factors for the corrections. All of the data visualization and analysis have been conducted using tableau analytics software, which facilitates the investigation of global and local events within an operation. The concept of using of handles and filters is proposed in this study, and it demonstrates the level of insight to the data and forms the basis of the outcomes obtained. This work shows that during operation, the engine performance is mostly deteriorating, though to varying degrees. Online washing also showed an influence on this, reducing the average degradation rate each hour by half, when compared to the engine operating only with offline washing. Hourly marginal improvements were also observed with an increased average wash frequency of nine hours and a similar outcome obtained when the washing solution is 2.3 times more concentrated. Clear benefits of offline washes are also presented, alongside the typically obtainable values of increased power output after a wash, also in relation to the number of operating hours before a wash.

Durability Testing of Biomass Based Oxygenated Fuel Components in a Compression Ignition Engine

2017 ◽  
Author(s):  
Marc E. Baumgardner ◽  
Arunachalam Lakshminarayanan ◽  
Daniel B. Olsen ◽  
Matthew A. Ratcliff ◽  
Robert L. McCormick ◽  
...  
Keyword(s):  
Diesel Fuel ◽  
Fuel Injection ◽  
Engine Performance ◽  
Engine Oil ◽  
Long Term Effects ◽  
Compression Ignition Engine ◽  
Engine Operation ◽  
Minimal Impact ◽  
Carbon Buildup ◽  
The Impact

Blending cellulosic biofuels with traditional petroleum-derived fuels results in transportation fuels with reduced carbon footprints. Many cellulosic fuels rely on processing methods that produce mixtures of oxygenates which must be upgraded before blending with traditional fuels. Complete oxygenate removal is energy-intensive and it is likely that such biofuel blends will necessarily contain some oxygen content to be economically viable. Previous work by our group indicated that diesel fuel blends with low levels (<4%-vol) of oxygenates resulted in minimal negative effects on short-term engine performance and emissions. However, little is known about the long-term effects of these compounds on engine durability issues such as the impact on fuel injection, in-cylinder carbon buildup, and engine oil degradation. In this study, four of the oxygenated components previously tested were blended at 4%-vol in diesel fuel and tested with a durability protocol devised for this work consisting of 200 hrs of testing in a stationary, single-cylinder, Yanmar diesel engine operating at constant load. Oil samples, injector spray patterns, and carbon buildup from the injector and cylinder surfaces were analyzed. It was found that, at the levels tested, these fuels had minimal impact on the overall engine operation, which is consistent with our previous findings.

Influence of pressure pulsation on the performance of compression system and turbocharged engine

2021 ◽  
pp. 095440702110304
Author(s):  
Zeng Hanxuan ◽  
Wang Baotong ◽  
Zou Wangzhi ◽  
Zheng Xinqian
Keyword(s):  
Pressure Pulsation ◽  
Combustion Engine ◽  
Characteristic Curve ◽  
Pressure Ratio ◽  
Engine Performance ◽  
Concave Function ◽  
Transient Pressure ◽  
Compression System ◽  
Compressor Inlet ◽  
The Impact

Pressure pulsation widely exists in power machinery combining compression components and pipelines. It has substantial effects on the performance of compressor as part of the compression system, as well as the engine. In this paper, the pressure pulsations under different excitation frequencies are measured and analyzed in the intake system of a turbo-charged and inter-cooled internal combustion engine. It is pointed out that the amplification of the pressure pulsation at the compressor inlet and outlet is caused by the coupling effects within the compression system, which consequently lead to the formation of a stable standing wave. Further research indicates that the pulsation at the compressor boundary will cause its pressure ratio to fluctuate. Additionally, because the compressor characteristic curve resembles a concave function, the fluctuation of transient pressure ratio will further cause the time-averaged pressure ratio to decline. Finally, the impact on engine performance is evaluated based on a well-validated simulation model.

scholarly journals Evaluation of the impact of the hydration degree of bioethanol on the operation parameters of the spark-ignition engine

2017 ◽  
Vol 169 (2) ◽  
pp. 71-75
Author(s):  
Marlena OWCZUK ◽  
Anna MATUSZEWSKA ◽  
Małgorzata ODZIEMKOWSKA ◽  
Mateusz BEDNARSKI ◽  
Marcin WOJS ◽  
...  
Keyword(s):  
Water Content ◽  
Engine Performance ◽  
Spark Ignition ◽  
Alcohol Concentration ◽  
Spark Ignition Engine ◽  
Cylinder Pressure ◽  
Engine Torque ◽  
Measurement Results ◽  
High Engine Speed ◽  
The Impact

The article presents an overview of methods for the production of bioethanol and the possibility of its use to power internalcombustion engines. The effects of supplying spark-ignition engine with bioethanol having various degrees of hydration were examined experimentally on the engine dynamometer. The measurement results were referred to the anhydrous bioethanol, which is used widely as petrol biocomponent and compared in terms of the course of the pressure in the combustion chamber of the engine as well as engine performance parameters – torque and power. It was found that with the decrease in alcohol concentration, the performance of the sparkignition engine deteriorated. The reduction of in-cylinder pressure was proportional to the increase in the water content in the fuel. No significant changes in the general shape of in-cylinder pressure curves were observed. Engine torque and power decreased with an increase in the water content in the fuel, especially at high engine speed. It has been stated that supplying the engine with bioethanol containing up to 6% (v/v) of water does not result in significant losses in engine performance.

Impact of Compressor Surge on Performance and Emissions of a Marine Diesel Engine

2016 ◽  
Vol 138 (10) ◽  
Author(s):  
Nikolaos-Alexandros Vrettakos
Keyword(s):  
Steady State ◽  
Diesel Engine ◽  
Engine Performance ◽  
Marine Diesel Engine ◽  
Performance Parameters ◽  
Test Bed ◽  
Engine Operation ◽  
Compressor Surge ◽  
Marine Diesel ◽  
The Impact

The operation during compressor surge of a medium speed marine diesel engine was examined on a test bed. The compressor of the engine's turbocharger was forced to operate beyond the surge line, by injecting compressed air at the engine intake manifold, downstream of the compressor during steady-state engine operation. While the compressor was surging, detailed measurements of turbocharger and engine performance parameters were conducted. The measurements included the use of constant temperature anemometry for the accurate measurement of air velocity fluctuations at the compressor inlet during the surge cycles. Measurements also covered engine performance parameters such as in-cylinder pressure and the impact of compressor surge on the composition of the exhaust gas emitted from the engine. The measurements describe in detail the response of a marine diesel engine to variations caused by compressor surge. The results show that both turbocharger and engine performance are affected by compressor surge and fast Fourier transform (FFT) analysis proved that they oscillate at the same main frequency. Also, prolonged steady-state operation of the engine with this form of compressor surge led to a non-negligible increase of NOx emissions.

scholarly journals Effect of boosting system architecture and thermomechanical limits on diesel engine performance: Part-I—Steady-state operation

2017 ◽  
Vol 19 (8) ◽  
pp. 854-872
Author(s):  
José Galindo ◽  
Hector Climent ◽  
Olivier Varnier ◽  
Chaitanya Patil
Keyword(s):  
Fuel Consumption ◽  
Combustion Engine ◽  
Engine Performance ◽  
Efficiency Optimization ◽  
Engine Model ◽  
Steady State Operation ◽  
Base Engine ◽  
And Performance ◽  
The Impact ◽  
Engine Development

Internal combustion engine developments are more focused on efficiency optimization and emission reduction for the upcoming future. To achieve these goals, technologies like downsizing and downspeeding are needed to be developed according to the requirement. These modifications on thermal engines are able to reduce fuel consumption and [Formula: see text] emission. However, implementation of these kind of technologies asks for right and efficient charging systems. This article consists of study of different boosting systems and architectures (single- and two-stage) with combination of different charging systems like superchargers and e-boosters. A parametric study is carried out with a zero-dimensional engine model to analyze and compare the effects of these different architectures on the same base engine. The impact of thermomechanical limits, turbo sizes and other engine development option characterizations are proposed to improve fuel consumption, maximum power and performance of the downsized/downspeeded diesel engines.

The impact of piston thermal barrier coating roughness on high-load diesel operation

2019 ◽  
pp. 146808741989348 ◽  
Author(s):  
Eric Gingrich ◽  
Michael Tess ◽  
Vamshi Korivi ◽  
Peter Schihl ◽  
John Saputo ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Surface Roughness ◽  
Thermal Barrier Coating ◽  
Engine Performance ◽  
Operating Conditions ◽  
Thermal Barrier ◽  
Engine Operation ◽  
Barrier Coating ◽  
The Impact ◽  
High Output

Thermal barrier coatings of various thickness and surface roughness were applied to the piston crown of a single-cylinder research engine and tested over a range of high-output diesel operating conditions, some near 30 bar gross indicated mean effective pressure. Three yttria-stabilized zirconia coated pistons were compared to a baseline metal piston. At each operating condition, a start-of-injection sweep was conducted to generate efficiency trends and find the optimal combustion phasing. Three variations of pistons coated with a graded-layer thermal barrier coating were tested: (1) 0.185 mm coating thickness with a surface roughness of approximately Ra = 11.8 µm, (2) 0.325 mm thickness with Ra = 11.8 µm, and (3) 0.325 mm thickness with Ra = 6.0 µm. Both coated pistons with Ra = 11.8 µm did not show any statistically significant improvement to engine performance when compared to the metal baseline piston, but did produce higher filter smoke numbers. The coated piston with Ra = 6.0 µm and 0.325 mm showed an increase of gross indicated thermal efficiency of up to 3.5% (relative) compared to the metal baseline piston for operating conditions comparable to standard engine operation and a reduction of filter smoke number back to the metal baseline. The increase in efficiency was found to correlate with additional late-cycle apparent heat release and a reduction in in-cylinder heat transfer. The very high-output conditions showed statistically insignificant changes in performance or heat transfer, which may have been related to the long injection duration used for these cases targeting outside of the piston bowl.

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