The Measurement of Component Friction Losses in a Fired Engine: Part 2 — Experimental Results

2005 ◽  
Author(s):  
Riaz A. Mufti ◽  
Martin Priest
Keyword(s):  
Engine Performance ◽  
Cost Effective ◽  
Operating Conditions ◽  
Experimental Results ◽  
Engine Oil ◽  
Sensor Technology ◽  
Component Level ◽  
Component Design ◽  
Engine Part ◽  
Actual Use

Bench testing can provide rapid and cost effective information for developing new lubricants. But there is general agreement that the only satisfactory means of evaluating the behaviour of engine oil is by actual use in engine. Also for detailed analysis of the tribological interaction it is important to analyse the engine performance at the component level. With the help of advance data acquisition system and sensor technology, experimental measurement of friction losses at the component level have been measured at realistic engine operating conditions, using the technique explained in Part 1. This paper describes the outcome of the experimental results at a range of engine operating conditions using mainly SAE 0W20 lubricant and some results from a friction-modified SAE 5W30 lubricant. The results clearly show considerable changes in the percentage contribution of power loss between low and high lubricant temperatures. The change in mode of lubricating regime from boundary to fluid film lubrication can be seen at the component level with increase in engine speed and decrease in lubricant temperature. This system can be used as a powerful tool for screening engine oils, analysing component design, validating friction models and studying the effect of different additives on the performance of each component under realistic operating conditions.

Preliminary Design of Variable Nozzle Turbines Based on Sensitive Parameters

2020 ◽  
Author(s):  
Sebastian Wittwer ◽  
Ivo Sandor
Keyword(s):  
Engine Performance ◽  
Optimal Solution ◽  
Operating Conditions ◽  
Experimental Results ◽  
Preliminary Design ◽  
Component Level ◽  
Gasoline Engines ◽  
Functional Parameters ◽  
Predictive Quality ◽  
Recent Developments

Abstract Recent developments in turbocharged gasoline engines have established new requirements for the turbine. A simple approach of scaling or optimizing existing turbines on component level might not be sufficient in terms of finding an optimal solution according to the multi-point, multi-disciplinary layout target. In the following paper nondimensional functional parameters are derived from turbomachinery analytics and rated on corresponding values of existing turbine stages. The influence of different parameters on aerodynamic performance is discussed based on CFD results and arranged according to their sensitivity for different engine relevant operating conditions. A metamodel for the preliminary design of variable nozzle turbine stages is derived from DoE (Design of Experiments) based CFD results. It is evaluated regarding its predictive quality on several exemplary turbine stages. Both, CFD and experimental results are therefore used while the experimental results are made up of hot gas stand measurements as well as measurements on engine test bench. Thus, not only the influence of functional parameters can be verified on turbine efficiency characteristics, but beyond that also the predictive quality of engine performance can be assessed.

Numerical Investigation of the Effects of Axial Cylinder Bore Profiles on Piston Ring Radial Dynamics

2003 ◽  
Vol 125 (4) ◽  
pp. 1081-1089 ◽  
Author(s):  
Y. Piao ◽  
S. D. Gulwadi
Keyword(s):  
High Speed ◽  
Piston Ring ◽  
Gasoline Engine ◽  
Engine Performance ◽  
Operating Conditions ◽  
Engine Oil ◽  
Oil Consumption ◽  
Ring Pack ◽  
Cylinder Bore

The role of cylinder bore shapes in engine performance has been the subject of several studies in recent years. In particular, the influence of bore distortion on oil consumption under high speed conditions has generated significant interest. In this paper, the effect of an axial bore profile on radial dynamics of a ring is investigated. Radial ring motions within grooves due to the axial bore profile can generate significant inertial effects and also have an impact on ring end-gap sizes and lubrication conditions at the ring-liner interfaces. The magnitude of such effects is dependent on the ring-pack configuration, engine operating conditions (speed and load) and axial bore profile details. These issues are investigated in this study due to their implication on engine oil consumption, friction and blow-by. The authors have developed an analytical expression to account for the effects of radial ring inertia due to an axial bore profile for implementation in a piston ring-pack simulation tool RINGPAK. Simulation results from a gasoline engine study are presented to illustrate the effects of engine speeds, ring tensions, and characteristics of axial bore profiles on ring radial dynamics and ring-liner lubrication. Relevant qualitative comparisons are made to experimental measurements available in the literature.

Random Forest Machine Learning Model for Predicting Combustion Feedback Information of a Natural Gas Spark Ignition Engine

2020 ◽  
Vol 143 (1) ◽  
Author(s):  
Jinlong Liu ◽  
Christopher Ulishney ◽  
Cosmin Emil Dumitrescu
Keyword(s):  
Machine Learning ◽  
Random Forest ◽  
Natural Gas ◽  
Engine Performance ◽  
Cost Effective ◽  
Learning Model ◽  
Operating Conditions ◽  
Control Variables ◽  
Feedback Information ◽  
Machine Learning Model

Abstract Engine calibration requires detailed feedback information that can reflect the combustion process as the optimized objective. Indicated mean effective pressure (IMEP) is such an indicator describing an engine’s capacity to do work under different combinations of control variables. In this context, it is of interest to find cost-effective solutions that will reduce the number of experimental tests. This paper proposes a random forest machine learning model as a cost-effective tool for optimizing engine performance. Specifically, the model estimated IMEP for a natural gas spark ignited engine obtained from a converted diesel engine. The goal was to develop an economical and robust tool that can help reduce the large number of experiments usually required throughout the design and development of internal combustion engines. The data used for building such correlative model came from engine experiments that varied the spark advance, fuel-air ratio, and engine speed. The inlet conditions and the coolant/oil temperature were maintained constant. As a result, the model inputs were the key engine operation variables that affect engine performance. The trained model was shown to be able to predict the combustion-related feedback information with good accuracy (R2 ≈ 0.9 and MSE ≈ 0). In addition, the model accurately reproduced the effect of control variables on IMEP, which would help narrow the choice of operating conditions for future designs of experiment. Overall, the machine learning approach presented here can provide new chances for cost-efficient engine analysis and diagnostics work.

Numerical Investigation of the Effects of Axial Cylinder Bore Profiles on Piston Ring Radial Dynamics

2002 ◽  
Author(s):  
Y. Piao ◽  
S. D. Gulwadi
Keyword(s):  
High Speed ◽  
Piston Ring ◽  
Gasoline Engine ◽  
Engine Performance ◽  
Operating Conditions ◽  
Engine Oil ◽  
Oil Consumption ◽  
Ring Pack ◽  
Cylinder Bore

The role of cylinder bore shapes in engine performance has been the subject of several studies in recent years. In particular, the influence of bore distortion on oil consumption under high speed conditions has generated significant interest. In this paper, the effect of an axial bore profile on radial dynamics of a ring is investigated. Radial ring motions within grooves due to the axial bore profile can generate significant inertial effects and also have an impact on ring end-gap sizes and lubrication conditions at the ring-liner interfaces. The magnitude of such effects is dependent on the ring-pack configuration, engine operating conditions (speed and load) and axial bore profile details. These issues are investigated in this study due to their implication on engine oil consumption, friction and blow-by. The authors have developed an analytical expression to account for the effects of radial ring inertia due to an axial bore profile for implementation in a piston ring–pack simulation tool RINGPAK. Simulation results from a gasoline engine study are presented to illustrate the effects of engine speeds, ring tensions and characteristics of axial bore profiles on ring radial dynamics and ring-liner lubrication. Relevant qualitative comparisons are made to experimental measurements available in the literature.

Modeling of Start-Up From Engine-Off Conditions Using High Fidelity Turbofan Engine Simulations

2015 ◽  
Vol 138 (5) ◽  
Author(s):  
Stefan Bretschneider ◽  
John Reed
Keyword(s):  
Development Process ◽  
Model Development ◽  
Engine Performance ◽  
Static Friction ◽  
Operating Conditions ◽  
High Fidelity ◽  
Turbofan Engine ◽  
Control Laws ◽  
Component Design ◽  
Start Up

Engine models are widely used to simulate the engine behavior at steady state and transient operating conditions over the full flight envelope. Within the engine development process such simulations are used to support component design, evaluate engine performance, operability and test data, as well as to develop and optimize the engine controls. Recent developments have raised interest in the modeling of start-up processes of turbofan engines in order to support the definition of sufficient engine control laws. This implies that simulations are started at a condition where the engine shafts are static and temperatures and pressures are equal to ambient. During start-up the engine can only be operated transiently through the sub-sub-idle region (near zero speed) using a starter torque. The activity presented here was targeted to support the development of industrial-standard high-fidelity turbofan engine models capable of simulating start-up, shutdown or windmilling operation. Within the three previously mentioned cases starting from an engine-off condition, ground start from zero-speed is the most challenging in terms of physical and numerical modeling. For this reason, this paper concentrates on that case only. Zero mass flow and speed at the beginning of the simulation impose a set of special problems that do not exist in standard simulations: the modeling of a static engine-off condition, the modeling of static friction, and the modeling of reverse flows. The requirement to support an existing industrial model development process also made it necessary to apply the same quality of physical modeling to start-up simulations as would be the case for above-idle engine simulations. The physical effects present during engine start are discussed and modeling solutions are presented. Finally, results of a dry crank simulation are presented and discussed, illustrating that the expected effects are present and that the simulation is capable of predicting the correct trends.

The Challenges of Uniform Crystal Temperature Sensor (UCTS) Application in Turbomachinery

2013 ◽  
Author(s):  
Justin Brown ◽  
Jason DeVoe ◽  
Lev Ginzbursky
Keyword(s):  
Temperature Sensor ◽  
Engine Performance ◽  
Cost Effective ◽  
Sensor Technology ◽  
Crystal Temperature ◽  
Element Analysis ◽  
Turbine Engine ◽  
Practical Reality ◽  
Test Instrumentation

The quality of information, which is necessary to help designers further improve turbine engine performance, requires sophisticated analytics working hand-in-hand with well-developed experimental methods. Historically, the test instrumentation used in harsh, real engine conditions was short-lived, invasive, and not very accurate. This was accepted as the practical reality and the data obtained in an engine test cell had been used as little more than a sanity check or a trend indicator during the design process. Today expectations are much higher and the challenge is to develop experimental tools that can deliver the accuracy required to verify analytical predictions, calibrate computer models and to provide ground for critical design decisions in a way which was not possible before. Successful introduction of UCTS (Uniform Crystal Temperature Sensor) Technology to the leading engine manufacturers demonstrated that it has the potential to overcome the typical issues of testing in a real engine environment. It is robust, non-intrusive and capable of high accuracy temperature measurement. It is based on the mechanism of heat transfer conduction, of which the fundamental theory is rigorous and simple. Our experience has shown that in order for a UCTS-based system to realize its promise, all potential sources of error must be tightly managed. LG Tech-Link identified important factors of influence that could complicate measurement and increase its uncertainty. Among them are variations in the part’s geometry, TBC thickness, boundary conditions, and installation methodology. These have been selected as the focus of this study. The authors of this paper are using 3D Finite Element Analysis (FEA) methodology to investigate the possible pitfalls in the process of UCTS application that could cause loss of accuracy. It is the authors’ intention to probe the sensitivity of temperature at the location of the sensor to the major technological factors. The findings emphasize the value of collaboration between instrumentation, test and analytical engineers when planning engine tests and interpreting their results. Practicing engineers will be able to use the presented recommendations, methodologies and case studies to ensure the application of UCTS in their projects is accurate, compatible with test objectives and cost effective.

Dynamic Characterization of Tilting Pad Journal Bearings From Component and System Level Testing

2012 ◽  
Author(s):  
Adolfo Delgado ◽  
Mirko Librashi ◽  
Giuseppe Vannini
Keyword(s):  
Stability Analysis ◽  
High Speed ◽  
Dynamic Stiffness ◽  
Operating Conditions ◽  
Logarithmic Decrement ◽  
Experimental Results ◽  
System Level ◽  
Component Level ◽  
Force Coefficients ◽  
Tilting Pad

The dynamic response of a direct lube, 5-pad, rocker-back pivot tilting pad bearing is characterized in a controlled motion (component level) test rig, and in a spin bunker (full system level) using a dummy rotor mounted on two identical bearings. In the component level test, the force coefficients (stiffness, damping, mass) are identified from pseudorandom excitations using a 2-DOF model. N-DOF system including the pad motions has been shown to yield frequency dependent coefficients that warrant the use of asynchronous coefficients for stability analysis in centrifugal compressors. However, experimental results showed that the real part of the dynamic stiffness is well represented as a constant stiffness and mass coefficients while the imaginary part yields a constant damping coefficient (i.e. frequency independent). In the system level test, a dedicated dummy rotor (representative of a high speed centrifugal compressor rotor) is excited by a magnetic shaker throughout a frequency range covering the rotor modes of interest while spinning at constant speed. From the rotor harmonic response the damping of each mode is extracted using a curve-fitting method based on a 1-DOF model for a given set of speeds. The dummy rotor test provides reference values for system logarithmic decrement and further validates the component level test results. The logarithmic decrement prediction using identified bearing force coefficients are in good agreement with the experimental results. In addition, using for prediction identified coefficients in a classical K-C-M or synchronous K-C form yields similar results (within 15%). This indicates that for the given bearing geometry (clearance, offset and size) and operating conditions, synchronously reduced force coefficients are adequate for stability analysis. Comparison of the identified force coefficients with results from commercially available code yielded reasonable agreement on direct coefficients while some discrepancies are highlighted on the cross-coupled coefficients.

Model Adaptation and Nonlinear Model Predictive Control of an Aircraft Engine

2004 ◽  
Author(s):  
Brent J. Brunell ◽  
Daniel E. Viassolo ◽  
Ravi Prasanth
Keyword(s):  
Model Predictive Control ◽  
Predictive Control ◽  
Nonlinear Model ◽  
Engine Performance ◽  
Aircraft Engine ◽  
Current Control ◽  
Operating Conditions ◽  
Nonlinear Model Predictive Control ◽  
Component Level ◽  
Output Constraints

The performance improvement of constrained nonlinear model predictive control (NMPC) with state and parameter estimation over traditional control architectures is investigated and applied to a model turbofan aircraft engine. Strong nonlinearities are present in turbofan aircraft engines due to the large range of operating conditions and power levels experienced during a typical mission. Also, turbine operation is restricted due to mechanical, aerodynamic, thermal, and flow limitations. Current control methodologies rely strictly on a priori information; therefore they fail to utilize current engine state or health information for reducing conservatism and improving engine performance. NMPC is selected because it depends on a model that can be adapted to the current engine conditions, it can explicitly handle the nonlinearities, both input and output constraints of many variables, and determine the optimal control that will meet the requirements for any engine condition all in a single control formulation. A physics based component level model is developed as the heart of the architecture. The state or health of the engine is determined using a joint state and parameter estimator utilizing extended Kalman filter (EKF) techniques. With the necessary engine information in hand, a constrained NMPC is used to determine the optimal actuator commands. Results regarding steady state performance improvements are presented.

A Gas Turbine Performance Simulation Program and Its Application to an IGCC Gas Turbine

2010 ◽  
Author(s):  
Jong Jun Lee ◽  
Young Sik Kim ◽  
Tong Seop Kim ◽  
Jeong Lak Sohn ◽  
Yong Jin Joo
Keyword(s):  
Gas Turbine ◽  
System Integration ◽  
Gas Turbines ◽  
Engine Performance ◽  
Operating Conditions ◽  
Simulation Program ◽  
Component Level ◽  
Performance Simulation ◽  
Blade Cooling ◽  
Variable Stator

This paper explains a performance simulation program for power generation gas turbines and its application to an IGCC gas turbine. The program has a modular structure and both the stage-level and entire component-level models were adopted. Stage-by-stage calculations were used in the compressor and the turbine. In particular, the compressor module is based on a stage-stacking method and is capable of simulating the effect of variable stator vanes. The combustor model has the capability of dealing with various fuels including syngas. The turbine module is capable of estimating blade cooling performance. The program can be easily extended to other applied cycles such as recuperated and reheated cycles because the program structure is fully modular. The program was verified for simple cycle commercial engines. In addition, the program was applied to the gas turbine in an IGCC plant. Influences of major system integration parameters on the operating conditions of the compressor and turbine as well as on engine performance were analyzed.

Features of the modern process of evaluation of motor oils References

2021 ◽  
Vol 05 ◽  
pp. 12-14
Author(s):  
A.L. Chudinovskikh ◽  
◽  
D.V. Boykov ◽  
Keyword(s):  
Internal Combustion Engine ◽  
Internal Combustion Engines ◽  
Combustion Engine ◽  
Internal Combustion ◽  
Point Of View ◽  
Operating Conditions ◽  
Engine Oil ◽  
Engine Part ◽  
General Aspects ◽  
Motor Oils

Changes in the design and parameters of modern internal combustion engines in order to achieve high economic, environmental, and other indicators lead to a tightening of the operating conditions of engine oil. Engine oil is an integral part of the internal combustion engine and from the point of view of modern views is positioned as an engine part. Currently, all internal combustion engine oils are generally tested, classified and evaluated according to generally accepted criteria and parameters. Without specifying and analyzing a whole layer of materials related to research, testing, evaluation of motor oils accumulated over more than a century, the article briefly discusses some general aspects of the classification and evaluation of oils for automotive equipment in leading foreign countries and the Russian Federation.

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