Vibration Spectra as a Feedback for Controlling Multicylinder Engine Performance

1992 ◽  
Vol 3 (2) ◽  
pp. 176-192
Author(s):  
T.W. Abou-Arab ◽  
M. Othman ◽  
Y.S.H. Najjar
Keyword(s):  
Engine Speed ◽  
Engine Performance ◽  
Feedback System ◽  
Operating Conditions ◽  
Flow Induced Vibration ◽  
Vibration Spectra ◽  
Parametric Studies ◽  
Vibration Pattern ◽  
Engine Components ◽  
Heat And Fluid Flow

Increasing requirements for vehicle confort, economy and reliability lead some investigators to consider the relationships between the mechanical vibrations with the heat and fluid flow induced vibration and noise in a more accurate manner. This paper describes the variation of the vibration phenomena associated with the motion of some engine components under different operating conditions. The measured vibration spectra indicates its capability in predicting symptoms of early engine failures, hence, expediting their control using a suitable feedback system. Parametric studies involving the effect of air-fuel ratio, ignition timing and engine speed on the vibration pattern are also carried out. These studies indicate that the amplitude of vibration decreases as the speed increases then increases again after certain engine speed. The effect of ignition system characteristic on the induced vibration are obtained and the correlation between the developed power and the engine dynamics over a range of operating conditions are discussed.

scholarly journals Numerical Analysis of Fuel Effects on Advanced Compression Ignition Using a Virtual Cooperative Fuel Research Engine Model

2020 ◽  
Author(s):  
Krishna C. Kalvakala ◽  
Pinaki Pal ◽  
Yunchao Wu ◽  
Goutham Kukkadapu ◽  
Christopher Kolodziej ◽  
...  
Keyword(s):  
Engine Speed ◽  
Driving Forces ◽  
Engine Performance ◽  
Kinetic Mechanism ◽  
Operating Conditions ◽  
Compression Ignition ◽  
Charge Condition ◽  
Engine Model ◽  
Primary Reference ◽  
Fuel Effects

Abstract Growing environmental concerns and demand for better fuel economy are driving forces that motivate the research for more advanced engines. Multi-mode combustion strategies have gained attention for their potential to provide high thermal efficiency and low emissions for light-duty applications. These strategies target optimizing the engine performance by correlating different combustion modes to load operating conditions. The extension from boosted SI mode at high loads to advanced compression ignition (ACI) mode at low loads can be achieved by increasing compression ratio and utilizing intake air heating. Further, in order to enable an accurate control of intake charge condition for ACI mode and rapid mode-switches, it is essential to gain fundamental insights into the autoignition process. Within the scope of ACI, homogeneous charge compression ignition (HCCI) mode is of significant interest. It is known for its potential benefits, operation at low fuel consumption, low NOx and PM emissions. In the present work, a virtual Cooperative Fuel Research (CFR) engine model is used to analyze fuel effects on ACI combustion. In particular, the effect of fuel Octane Sensitivity (S) (at constant RON) on autoignition propensity is assessed under beyond-RON (BRON) and beyond-MON (BMON) ACI conditions. The 3D CFR engine computational fluid dynamics (CFD) model employs finite-rate chemistry approach with multi-zone binning strategy to capture autoignition. Two binary blends with Research Octane Number (RON) of 90 are chosen for this study: Primary reference fuel (PRF) with S = 0, and toluene-heptane (TH) blend with S = 10.8, representing paraffinic and aromatic gasoline surrogates. Reduced mechanisms for these blends are generated from a detailed gasoline surrogate kinetic mechanism. Simulation results with the reduced mechanisms are validated against experimental data from an in-house CFR engine, with respect to in-cylinder pressure, heat release rate and combustion phasing. Thereafter, the sensitivity of combustion behavior to ACI operating condition (BRON vs BMON), air-fuel ratio (λ = 2 and 3), and engine speed (600 and 900rpm) is analyzed for both fuels. It is shown that the sensitivity of a fuel’s autoignition characteristics to λ and engine speed significantly differs at BRON and BMON conditions. Moreover, this sensitivity is found to vary among fuels, despite the same RON. This study also indicates that the octane index (OI) fails to capture the trend in the variation of autoignition propensity with S under BMON conditions.

Instructing the Principles of Gas Turbine Performance Monitoring and Diagnostics by Means of Interactive Computer Models

2000 ◽  
Author(s):  
K. Mathioudakis ◽  
A. Stamatis ◽  
A. Tsalavoutas ◽  
N. Aretakis
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Performance Monitoring ◽  
Measurement Data ◽  
Engine Performance ◽  
Performance Model ◽  
Operating Conditions ◽  
Engine Operation ◽  
Turbine Performance ◽  
Engine Components

The paper discusses how the principles employed for monitoring the performance of gas turbines in industrial duty can be explained by using suitable Gas Turbine performance models. A particular performance model that can be used for educational purposes is presented. The model allows the presentation of basic rules of gas turbine engine behavior and helps understanding different aspects of its operation. It is equipped with a graphics interface, so it can present engine operating point data in a number of different ways: operating line, operating points of the components, variation of particular quantities with operating conditions etc. Its novel feature, compared to existing simulation programs, is that it can be used for studying cases of faulty engine operation. Faults can be implanted into different engine components and their impact on engine performance studied. The notion of fault signatures on measured quantities is clearly demonstrated. On the other hand, the model has a diagnostic capability, allowing the introduction of measurement data from faulty engines and providing a diagnosis, namely a picture of how the performance of engine components has deviated from nominal condition, and how this information gives the possibility for fault identification.

Experimental Investigation on Biodiesel-Ethanol-Diesel Blends Operating with a Diesel Engine

2013 ◽  
Vol 465-466 ◽  
pp. 221-225 ◽  
Author(s):  
Mohd Hafizil Mat Yasin ◽  
Rizalman Mamat ◽  
Abdul Mutalib Leman ◽  
Amir Khalid ◽  
Noreffendy Tamaldin
Keyword(s):  
Experimental Investigation ◽  
Diesel Engine ◽  
Fuel Consumption ◽  
Engine Speed ◽  
Ethanol Concentration ◽  
Engine Performance ◽  
Operating Conditions ◽  
Brake Specific Fuel Consumption ◽  
Ethanol Blends ◽  
No Emissions

Biodiesel is an alternative, decomposable and biological-processed fuel that has similar characteristics with mineral diesel which can be used directly into diesel engines. However, biodiesel has its drawbacks which are more density and viscosity compared to mineral diesel. Alcohol additives implementation such as ethanol could reduce significantly the density and viscosity of the biodiesel. In this study, biodiesel (20%)-ethanol (5%)-diesel (75%), biodiesel (20%)-methanol (10%)-diesel (70%), biodiesel (20%)-ethanol (15%)-diesel (65%), biodiesel (20%)-ethanol (20%)-diesel (60%) and standard mineral diesel as a baseline fuel are tested in a Mitsubishi 4D68 diesel engine. Those test fuels are investigated under the same operating conditions at three different engine loads; 20%, 40% and 60% at a constant engine speed of 2500 rpm to determine the engine performance, combustion and emission of the diesel engine. Overall, biodiesel-ethanol-diesel blends show higher brake specific fuel consumption than mineral diesel especially at higher ethanol concentration. As ethanol proportions in blends increase, CO emissions increase, while NO emissions are reduced. Also, biodiesel-ethanol blend with 5% ethanol is more effective than other biodiesel-ethanol blends for reducing CO emissions and improve the combustion.

NUMERICAL ANALYSIS OF FUEL EFFECTS ON ADVANCED COMPRESSION IGNITION USING A COOPERATIVE FUEL RESEARCH ENGINE COMPUTATIONAL FLUID DYNAMICS MODEL

2021 ◽  
pp. 1-34
Author(s):  
Krishna C Kalvakala ◽  
Pinaki Pal ◽  
Yunchao Wu ◽  
Goutham Kukkadapu ◽  
Christopher Kolodziej ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Heat Release ◽  
Engine Speed ◽  
Driving Forces ◽  
Engine Performance ◽  
Operating Conditions ◽  
Compression Ignition ◽  
Charge Condition ◽  
Fuel Effects

Abstract Growing environmental concerns and demand for better fuel economy are driving forces that motivate the research for more advanced engines. Multi-mode combustion strategies have gained attention for their potential to provide high thermal efficiency and low emissions for light-duty applications. These strategies target optimizing the engine performance by correlating different combustion modes to load operating conditions. The extension from boosted SI mode at high loads to advanced compression ignition (ACI) mode at low loads can be achieved by increasing compression ratio and utilizing intake air heating. Further, in order to enable an accurate control of intake charge condition for ACI mode and rapid mode-switches, it is essential to gain fundamental insights into the autoignition process. Within the scope of ACI, homogeneous charge compression ignition (HCCI) mode is of significant interest. It is known for its potential benefits, operation at low fuel consumption, low NOx and PM emissions. In the present work, a virtual Cooperative Fuel Research (CFR) engine model is used to analyze fuel effects on ACI combustion. In particular, the effect of fuel Octane Sensitivity (S) (at constant RON) on autoignition propensity is assessed under beyond-RON (BRON) and beyond-MON (BMON) ACI conditions. The 3D CFR engine computational fluid dynamics (CFD) model employs finite-rate chemistry approach with multi-zone binning strategy to capture autoignition. Two binary blends with Research Octane Number (RON) of 90 are chosen for this study: Primary reference fuel (PRF) with S = 0, and toluene-heptane (TH) blend with S = 10.8, representing paraffinic and aromatic gasoline surrogates. Reduced mechanisms for these blends are generated from a detailed gasoline surrogate kinetic mechanism. Simulation results with the reduced mechanisms are validated against experimental data from an in-house CFR engine, with respect to in-cylinder pressure, heat release rate and combustion phasing. Thereafter, the sensitivity of combustion behavior to ACI operating condition (BRON vs BMON), air-fuel ratio (λ = 2 and 3), and engine speed (600 and 900rpm) is analyzed for both fuels. It is shown that the sensitivity of a fuel's autoignition characteristics to λ and engine speed significantly differs at BRON and BMON conditions. Moreover, this sensitivity is found to vary among fuels, despite the same RON. It is also observed that the presence of low temperature heat release (LTHR) under BRON condition leads to more sequential autoignition and longer combustion duration than BMON condition. Finally, the study indicates that the octane index (OI) fails to capture the trend in the variation of autoignition propensity with S under BMON condition.

Experimental Evaluation of Turbo-Matching Appropriateness of B60J67, B60J68, A58N70 and A58N72 Turbo-Chargers for a Commercial Vehicle Engine

2018 ◽  
Vol 6 (11) ◽  
pp. 71
Author(s):  
Badal Dev Roy ◽  
R. Saravanan
Keyword(s):  
Internal Combustion Engines ◽  
Perfect Match ◽  
Engine Performance ◽  
Operating Conditions ◽  
Data Logger ◽  
Negative Effects ◽  
Road Test ◽  
The Road ◽  
A Charge ◽  
All Speeds

The Turbocharger is a charge booster for internal combustion engines to ensure best engine performance at all speeds and road conditions especially at the higher load.  Random selection of turbocharger may lead to negative effects like surge and choke in the breathing of the engine. Appropriate selection or match of the turbocharger (Turbomatching) is a tedious task and expensive. But perfect match gives many distinguished advantages and it is a one time task per the engine kind. This study focuses to match the turbocharger to desired engine by simulation and on road test. The objective of work is to find the appropriateness of matching of turbochargers with trim 67 (B60J67), trim 68 (B60J68),  trim 70 (A58N70) and trim 72 (A58N72) for the TATA 497 TCIC -BS III engine. In the road-test (data-logger method) the road routes like highway and slope up were considered for evaluation. The operating conditions with respect various speeds, routes and simulated outputs were compared with the help of compressor map.

scholarly journals Optimal Tuner Selection for Kalman Filter-Based Aircraft Engine Performance Estimation

2009 ◽  
Vol 132 (3) ◽  
Author(s):  
Donald L. Simon ◽  
Sanjay Garg
Keyword(s):  
Kalman Filter ◽  
Estimation Error ◽  
Engine Performance ◽  
Aircraft Engine ◽  
Operating Conditions ◽  
Performance Estimation ◽  
Experimental Simulation ◽  
Tuning Parameter ◽  
Estimation Accuracy ◽  
On Line

A linear point design methodology for minimizing the error in on-line Kalman filter-based aircraft engine performance estimation applications is presented. This technique specifically addresses the underdetermined estimation problem, where there are more unknown parameters than available sensor measurements. A systematic approach is applied to produce a model tuning parameter vector of appropriate dimension to enable estimation by a Kalman filter, while minimizing the estimation error in the parameters of interest. Tuning parameter selection is performed using a multivariable iterative search routine that seeks to minimize the theoretical mean-squared estimation error. This paper derives theoretical Kalman filter estimation error bias and variance values at steady-state operating conditions, and presents the tuner selection routine applied to minimize these values. Results from the application of the technique to an aircraft engine simulation are presented and compared with the conventional approach of tuner selection. Experimental simulation results are found to be in agreement with theoretical predictions. The new methodology is shown to yield a significant improvement in on-line engine performance estimation accuracy.

Two-Stroke Marine Diesel Engine Variable Injection Timing System Performance Evaluation and Optimum Setting for Minimum Fuel Consumption at Acceptable NOx Levels

2014 ◽  
Author(s):  
Dimitrios T. Hountalas ◽  
Spiridon Raptotasios ◽  
Antonis Antonopoulos ◽  
Stavros Daniolos ◽  
Iosif Dolaptzis ◽  
...  
Keyword(s):  
Diesel Engine ◽  
Fuel Consumption ◽  
Engine Performance ◽  
Operating Conditions ◽  
Specific Fuel Consumption ◽  
Injection Timing ◽  
Nox Emissions ◽  
Pressure Measurements ◽  
Cylinder Pressure ◽  
Start Of Injection

Currently the most promising solution for marine propulsion is the two-stroke low-speed diesel engine. Start of Injection (SOI) is of significant importance for these engines due to its effect on firing pressure and specific fuel consumption. Therefore these engines are usually equipped with Variable Injection Timing (VIT) systems for variation of SOI with load. Proper operation of these systems is essential for both safe engine operation and performance since they are also used to control peak firing pressure. However, it is rather difficult to evaluate the operation of VIT system and determine the required rack settings for a specific SOI angle without using experimental techniques, which are extremely expensive and time consuming. For this reason in the present work it is examined the use of on-board monitoring and diagnosis techniques to overcome this difficulty. The application is conducted on a commercial vessel equipped with a two-stroke engine from which cylinder pressure measurements were acquired. From the processing of measurements acquired at various operating conditions it is determined the relation between VIT rack position and start of injection angle. This is used to evaluate the VIT system condition and determine the required settings to achieve the desired SOI angle. After VIT system tuning, new measurements were acquired from the processing of which results were derived for various operating parameters, i.e. brake power, specific fuel consumption, heat release rate, start of combustion etc. From the comparative evaluation of results before and after VIT adjustment it is revealed an improvement of specific fuel consumption while firing pressure remains within limits. It is thus revealed that the proposed method has the potential to overcome the disadvantages of purely experimental trial and error methods and that its use can result to fuel saving with minimum effort and time. To evaluate the corresponding effect on NOx emissions, as required by Marpol Annex-VI regulation a theoretical investigation is conducted using a multi-zone combustion model. Shop-test and NOx-file data are used to evaluate its ability to predict engine performance and NOx emissions before conducting the investigation. Moreover, the results derived from the on-board cylinder pressure measurements, after VIT system tuning, are used to evaluate the model’s ability to predict the effect of SOI variation on engine performance. Then the simulation model is applied to estimate the impact of SOI advance on NOx emissions. As revealed NOx emissions remain within limits despite the SOI variation (increase).

scholarly journals Development and Testing of a Methodology for the Assessment of Acceptability of LKA Systems

Machines ◽  
2020 ◽  
Vol 8 (3) ◽  
pp. 47 ◽  
Author(s):  
Luca Salvati ◽  
Matteo d’Amore ◽  
Anita Fiorentino ◽  
Arcangelo Pellegrino ◽  
Pasquale Sena ◽  
...  
Keyword(s):  
Force Feedback ◽  
Feedback System ◽  
Operating Conditions ◽  
Experimental Methodology ◽  
Driving Safety ◽  
Steering Wheel ◽  
Human In The Loop ◽  
Automation Systems ◽  
Driving Stability ◽  
Lane Keeping

In recent years, driving simulators have been widely used by automotive manufacturers and researchers in human-in-the-loop experiments, because they can reduce time and prototyping costs, and provide unlimited parametrization, more safety, and higher repeatability. Simulators play an important role in studies about driver behavior in operating conditions or with unstable vehicles. The aim of the research is to study the effects that the force feedback (f.f.b.), provided to steering wheel by a lane-keeping-assist (LKA) system, has on a driver’s response in simulators. The steering’s force feedback system is tested by reproducing the conditions of criticality of the LKA system in order to minimize the distance required to recover the driving stability as a function of set f.f.b. intensity and speed. The results, obtained in three specific criticality conditions, show that the behaviour of the LKA system, reproduced in the simulator, is not immediately understood by the driver and, sometimes, it is in opposition with the interventions performed by the driver to ensure driving safety. The results also compare the performance of the subjects, either overall and classified into subgroups, with reference to the perception of the LKA system, evaluated by means of a questionnaire. The proposed experimental methodology is to be regarded as a contribution for the integration of acceptance tests in the evaluation of automation systems.

Characteristics of Water-in-Diesel Emulsions in a Single Cylinder Compression Ignition Engine

2014 ◽  
Author(s):  
Teja Gonguntla ◽  
Robert Raine ◽  
Leigh Ramsey ◽  
Thomas Houlihan
Keyword(s):  
Fuel Consumption ◽  
Direct Injection ◽  
Engine Performance ◽  
Operating Conditions ◽  
Specific Fuel Consumption ◽  
Brake Specific Fuel Consumption ◽  
Compression Ignition Engine ◽  
Oil Emulsion ◽  
Single Cylinder ◽  
Performance And Emission

The objective of this project was to develop both engine performance and emission profiles for two test fuels — a 6% water-in-diesel oil emulsion (DOE-6) fuel and a neat diesel (D100) fuel. The testing was performed on a single cylinder, direct-injection, water-cooled diesel engine coupled to an eddy current dynamometer. Output parameters of the engine were used to calculate Brake Specific Fuel Consumption (BSFC) and Engine Efficiency (η) for each test fuel. DOE-6 fuels generated a 24% reduction in NOX and a 42% reduction in Carbon Monoxide emissions over the tested operating conditions. DOE-6 fuels presented higher ignition delays — between 1°-4°, yielded 1%–12% lower peak cylinder pressures and produced up to 5.5% lower exhaust temperatures. Brake Specific Fuel consumption increased by 6.6% for the DOE-6 fuels as compared to the D100 fuels. This project is the first research done by a New Zealand academic institution on water-in-diesel emulsion fuels.

scholarly journals CFD Study of Nozzle Configurations for Ultra High Bypass Engines

1993 ◽  
Author(s):  
H. Zimmermann ◽  
R. Gumucio ◽  
K. Katheder ◽  
A. Jula
Keyword(s):  
Engine Performance ◽  
Operating Conditions ◽  
Aerodynamic Design ◽  
Thrust Coefficient ◽  
Optimum Range ◽  
Installation Effects ◽  
Wide Range ◽  
And Performance ◽  
Aircraft Aerodynamics ◽  
Bypass Ratio

Performance and aerodynamic aspects of ultra-high bypass ratio ducted engines have been investigated with an emphasis on nozzle aerodynamics. The interference with aircraft aerodynamics could not be covered. Numerical methods were used for aerodynamic investigations of geometrically different aft end configurations for bypass ratios between 12 and 18, this is the optimum range for long missions which will be important for future civil engine applications. Results are presented for a wide range of operating conditions and effects on engine performance are discussed. The limitations for higher bypass ratios than 12 to 18 do not come from nozzle aerodynamics but from installation effects. It is shown that using CFD and performance calculations an improved aerodynamic design can be achieved. Based on existing correlations, for thrust and mass-flow, or using aerodynamic tailoring by CFD and including performance investigations, it is possible to increase the thrust coefficient up to 1%.

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