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.

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.

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.

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.

Spike and Modal Stall Inception in an Advanced Turbocharger Centrifugal Compressor

2009 ◽  
Vol 131 (3) ◽  
Author(s):  
Z. S. Spakovszky ◽  
C. H. Roduner
Keyword(s):  
Centrifugal Compressor ◽  
High Speed ◽  
Pressure Ratio ◽  
Pressure Sensors ◽  
Rotating Stall ◽  
Vaned Diffuser ◽  
Stall Inception ◽  
Compression System ◽  
The Impact ◽  
Highly Loaded

In turbocharger applications, bleed air near the impeller exit is often used for secondary flow systems to seal bearing compartments and to balance the thrust load on the bearings. There is experimental evidence that the performance and operability of highly-loaded centrifugal compressor designs can be sensitive to the amount of bleed air. To investigate the underlying mechanisms and to assess the impact of bleed air on the compressor dynamic behavior, a research program was carried out on a preproduction, 5.0 pressure ratio, high-speed centrifugal compressor stage of advanced design. The investigations showed that bleed air can significantly reduce the stable flow range. Compressor rig experiments, using an array of unsteady pressure sensors and a bleed valve to simulate a typical turbocharger environment, suggest that the path into compression system instability is altered by the bleed flow. Without the bleed flow, the prestall behavior is dominated by short-wavelength disturbances, or so called “spikes,” in the vaneless space between the impeller and the vaned diffuser. Introducing bleed flow at the impeller exit reduces endwall blockage in the vaneless space and destabilizes the highly-loaded vaned diffuser. The impact is a 50% reduction in stable operating range. The altered diffuser characteristic reduces the compression system damping responsible for long-wavelength modal prestall behavior. A four-lobed backward traveling rotating stall wave is experimentally measured in agreement with calculations obtained from a previously developed dynamic compressor model. In addition, a self-contained endwall blockage control strategy was employed, successfully recovering 75% of the loss in surge-margin due to the bleed flow and yielding a one point increase in adiabatic compressor efficiency.

scholarly journals The impact of the simple orifice schemes of the buffer device in boom refuelling system in the transient pressure of the pipeline

2021 ◽  
Vol 233 ◽  
pp. 04015
Author(s):  
Zhangzhi Dong ◽  
Xiaogang Li ◽  
Yanyan Hou ◽  
Bin Li ◽  
Yujuan He
Keyword(s):  
System Reliability ◽  
Pressure Pulsation ◽  
Simulation Analysis ◽  
Pipeline System ◽  
Transient Pressure ◽  
Pressure Shock ◽  
Flow Area ◽  
Suppression Effect ◽  
Pressure Peak ◽  
The Impact

The boom refuelling system has a large refueling flow, and the refueling joint when the refueling is interrupted in an emergency will cause pressure shock and pressure pulsation. In severe cases, it will cause vibration of the pipeline system, reduce system reliability, and seriously endanger flight safety. Adding a device similar to an accumulator at the end of the pipeline where pressure shock occurs can well absorb the shock pressure. This paper uses a certain type of aircraft as a background to simulate the construction of a rigid air refueling pipeline system with a buffer device. The emphasis is on the pressure shock suppression characteristics of the buffer device. The simulation analysis of the opening parameters of the expansion cavity entrance includes the number and size of the buffer device. The impact of pressure shock performance. The results show that: the more openings and the larger the pore size, the larger the first pressure peak and the smaller the second pressure peak; while increasing the total flow area can effectively reduce the pressure shock suppression effect of the buffer device.

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.

Spike and Modal Stall Inception in an Advanced Turbocharger Centrifugal Compressor

2007 ◽  
Author(s):  
Z. S. Spakovszky ◽  
C. H. Roduner
Keyword(s):  
Centrifugal Compressor ◽  
High Speed ◽  
Pressure Ratio ◽  
Pressure Sensors ◽  
Rotating Stall ◽  
Vaned Diffuser ◽  
Stall Inception ◽  
Compression System ◽  
The Impact ◽  
Highly Loaded

In turbocharger applications bleed air near the impeller exit is often used for secondary flow systems to seal bearing compartments and to balance the thrust load on the bearings. There is experimental evidence that the performance and operability of highly loaded centrifugal compressor designs can be sensitive to the amount of bleed air. To investigate the underlying mechanisms and to assess the impact of bleed air on the compressor dynamic behavior, a research program was carried out on a pre-production, 5.0 pressure ratio, high-speed centrifugal compressor stage of advanced design. The investigations showed that bleed air can significantly reduce the stable flow range. Compressor rig experiments, using an array of unsteady pressure sensors and a bleed valve to simulate a typical turbocharger environment, suggest that the path into compression system instability is altered by the bleed flow. Without bleed flow, the pre-stall behavior is dominated by short wavelength disturbances, or so called ‘spikes’, in the vaneless space between the impeller and the vaned diffuser. Introducing bleed flow at impeller exit reduces endwall blockage in the vaneless space and destabilizes the highly-loaded vaned diffuser. The impact is a 50% reduction in stable operating range. The altered diffuser characteristic reduces the compression system damping responsible for long wavelength, modal pre-stall behavior. A four-lobed backward traveling rotating stall wave is experimentally measured, in agreement with calculations obtained from a previously developed dynamic compressor model. In addition, a self-contained, endwall blockage control strategy was employed, successfully recovering 75% of the loss in surge-margin due to bleed flow and yielding a 1 point increase in adiabiatic compressor efficiency.

A One-Dimensional Investigation of the Effect of an Active Control Turbocharger on Internal Combustion Engine Performance

2011 ◽  
Author(s):  
Apostolos Pesiridis ◽  
Benjamin Dubois ◽  
Ricardo F. Martinez-Botas
Keyword(s):  
Internal Combustion Engine ◽  
Fuel Consumption ◽  
Active Control ◽  
Combustion Engine ◽  
Engine Performance ◽  
Internal Combustion ◽  
Simulation Software ◽  
Boost Pressure ◽  
Turbine Inlet ◽  
The Impact

The present paper discusses the impact of a new type of turbocharger, namely, the Active Control Turbocharger (ACT). The aim of this work was to prove the advantage of this type of turbocharger over the current state-of-the-art: the Variable Geometry Turbocharger (VGT). This was achieved by carrying out a comparison between two commercial Diesel engine models (through the use of a commercial engine simulation software), which belong to the same family: one 10 litre engine equipped with VGT (originally) was consecutively compared to the same model of engine modified for ACT operation and through the integration of the ACT into the 81 version of the same engine in order to demonstrate the ACT’s downsizing capability. The study has been carried out for speeds between 800 and 2000 rpm, and a fuel-air ratio range of between 0.017 and 0.057. The results showed that the actuation of the turbine in ACT mode (through the sinusoidal regulation of the turbine inlet area with each incoming exhaust gas pressure pulse) increases greatly the energy available at the turbine inlet. This leads to an increase of the boost pressure at the intake of the engine by an average 30%. The specific fuel consumption was found to be similar throughout engine operating range with a penalty of up to 10% for the ACT engine of the same size (10 litre). A comparison was then carried out between the 10 litre VGT engine and the 8 litre ACT engine. The 8 litre has been found to produce up to 37% more torque and horse power under 1400 rpm and obtained very similar performance to the 10 litre VGT engine at higher speeds. At constant power output between the 8 and 10 litre engines, it has been found that the fuel consumption was decreased by a maximum of 9% when using the 8 litre engine. The results of the present study were encouraging with respect to the potential of ACT to downsize the internal combustion engine.

scholarly journals Effect of boosting system architecture and thermomechanical limits on diesel engine performance: Part II—transient operation

2017 ◽  
Vol 19 (8) ◽  
pp. 873-885 ◽  
Author(s):  
José Galindo ◽  
Hector Climent ◽  
Olivier Varnier ◽  
Chaitanya Patil
Keyword(s):  
Fuel Consumption ◽  
Combustion Engine ◽  
Test Procedure ◽  
Engine Performance ◽  
Pollutant Emissions ◽  
Engine Model ◽  
Performance And Emissions ◽  
And Performance ◽  
Transient Operations ◽  
The Impact

Nowadays, internal combustion engine developments are focused on efficiency optimization and emission reduction. Increasing focus on world harmonized ways to determine the performance and emissions on Worldwide harmonized Light vehicles Test Procedure cycles, it is essential to optimize the engines for transient operations. To achieve these objectives, the downsized or downspeeded engines are required, which can reduce fuel consumption and pollutant emissions. However, these technologies ask for efficient charging systems. This article consists of the study of different boosting architectures (single stage and two stage) with a combination of different charging systems like superchargers and e-boosters. A parametric study has been carried out with a zero-dimensional engine model to analyze and compare different architectures on the different engine displacements. The impact of thermomechanical limits, turbo sizes and other engine development option characterizations is proposed to improve fuel consumption, maximum power and performance of the downsized/downspeeded diesel engines during the transient operations.

Fluidics in Aircraft Engine Controls

1981 ◽  
Vol 103 (4) ◽  
pp. 324-330 ◽  
Author(s):  
G. E. Davies
Keyword(s):  
Pressure Ratio ◽  
Engine Performance ◽  
Aircraft Engine ◽  
Appropriate Technology ◽  
Engine Fuel ◽  
Engine Control System ◽  
Fuel Flow ◽  
Basic Engine ◽  
Wide Range ◽  
Compressor Inlet

Fluidics is a particularly appropriate technology for engine controls as it is capable of measuring pressure ratio, one of the basic engine performance parameters, as a fundamental quantity. This results in improved accuracy of measurement and obviates the need of conventional systems to utilize nonoptimum, but easier to measure, control parameters. A wide range of aircraft engine controls has been developed covering controls for compressor inlet guide vanes, compressor bleed valves, engine fuel flow including engine instrumentation. Total fluidic unit deliveries exceed 4200 and the civil operating hours exceed 13.5 million. As a further development, a completely fluidic engine control system is proposed with an electronic computer controlled secondary control or trim system for efficiency optimization.

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