scholarly journals The analysis of vibrations in the vehicle with naturally aspirated and turbocharged gasoline engine

2020 ◽  
Vol 181 (2) ◽  
pp. 19-23
Author(s):  
Łukasz ŁOZA
Keyword(s):  
Gasoline Engine ◽  
Primary Source ◽  
Measuring Method ◽  
Passenger Cars ◽  
Engine Operation ◽  
Gasoline Engines ◽  
Natural Operation ◽  
Vehicle Structure ◽  
Entire Vehicle ◽  
The Time Domain

In this paper, the author presents a study of vibrations in a passenger vehicle and the possible influence on driver’s body in the process of natural operation. The author describes the dependence of engine size and additional equipment as the possible primary source of the vibration variations and their further propagation in the entire vehicle structure. The analysis was performed on the passenger cars with naturally aspirated and turbocharged gasoline engines. The aim of this study was to verify the level of vibrations in the vehicle structure with these particular engines, especially influence of downsized power unit, during various state of engine operation. The second goal was to examine the vibrations in the specified location related to driver’s body. The measuring method used piezoelectric accelerometers, which were attached to the designated locations in the vehicle and were able to detect variations of the acceleration. The signals were collected as characteristics in the time domain. In order to achieve frequency domain for spectral analyses, the author applied the Fast Fourier Transform (FFT).

scholarly journals The analysis of vibrations of gasoline and diesel vehicles as a function of their engine sizes

2019 ◽  
Vol 178 (3) ◽  
pp. 20-23
Author(s):  
Łukasz ŁOZA ◽  
Radosław WRÓBEL ◽  
Lech SITNIK
Keyword(s):  
Laser Doppler Vibrometer ◽  
Primary Source ◽  
Complex Signal ◽  
Damping Factor ◽  
Specific Information ◽  
Passenger Cars ◽  
Engine Operation ◽  
Diesel Vehicles ◽  
Entire Structure ◽  
The Time Domain

This paper presents a study of vibrations appearing in a vehicle in the process of its operation. The authors describe the primary source of the vibrations and their propagation in the entire structure. The observations were performed on the passenger cars with vari-ous gasoline and diesel engines. The aim was to examine the level of damping factor in the different locations in the car, precisely speci-fied for the purpose of this studies. The secondary goal was to develop an effective method of obtaining and analyzing signals generated during the engine operation. The chosen instrument was Laser Doppler Vibrometer (LDV), which is used as the non-intrusive measure-ment utensil to detect velocity variations in designated places. The signals are gathered and collected as group of sinusoidal characteris-tics in the time domain. In order to achieve specific information about every component of the original signal, the authors apply Fast Fourier Transform (FFT) as the analyzing method. It allows to distinct the basic sinusoidal characteristics in the frequency domain through the spectral analysis. Based on the results, the authors are able to distinguish the dominant modes from the complex signal and indicate their impact on the car.

Statistical Quantification of Knock With Spark Ignition and Pre-Chamber Jet Ignition in a Light Duty Gasoline Engine

2020 ◽  
Author(s):  
Xin Yu ◽  
Anqi Zhang ◽  
Andrew Baur ◽  
Alexander Voice ◽  
Nayan Engineer
Keyword(s):  
Gasoline Engine ◽  
Pressure Oscillation ◽  
Spark Ignition ◽  
Engine Operation ◽  
Gasoline Engines ◽  
Higher Temperature ◽  
Gas Circulation ◽  
Temperature And Pressure ◽  
Ignition And Combustion ◽  
Random Nature

Abstract Knock is a major challenge for high load operation of spark ignited gasoline engines with higher compression ratios, since the end-gas undergoes higher temperature and pressure trajectories during combustion. Pre-chamber combustion creates long-reach ignition jets that have the potential to mitigate knock due to their rapid consumption of end-gas. However, conventional pressure oscillation-based knock metrics may not accurately capture the end-gas autoignition severity in pre-chamber systems due to differences in ignition and combustion behavior. This work investigates the knock behavior of both traditional spark ignition and pre-chamber combustion (including different nozzle designs) in a high compression ratio engine fueled with regular octane certification gasoline. The data was analyzed using statistical methods to show the random nature of knock events. Detailed analysis was used to explain the pressure oscillations of both knocking and non-knocking cycles of pre-chamber jet combustion and show that conventional pressure oscillation-based knock metrics may not adequately quantify end-gas autoignition severity. A novel knock metric is introduced to avoid consideration of the non-knock related pressure oscillation and better quantify the end-gas autoignition severity. The new metric was used to explain the knock mitigation mechanism for pre-chamber jet combustion and demonstrate an additional pre-chamber jet ignition benefit of reduced combustion variability during engine operation with cooled exhaust gas circulation within its dilution limit.

Future gasoline engine ignition: A review on advanced concepts

2020 ◽  
pp. 146808742095308
Author(s):  
Shui Yu ◽  
Ming Zheng
Keyword(s):  
High Efficiency ◽  
Gasoline Engine ◽  
Empirical Work ◽  
High Energy ◽  
Charge Motion ◽  
Engine Operation ◽  
Gasoline Engines ◽  
Implementation Challenges ◽  
Plasma Ignition ◽  
Discharge Ignition

To meet the future requirements of fuel economy and exhaust emissions, high-efficiency gasoline engines tend to employ diluted combustion concepts along with intensified charge motion and stratified mixtures. Securing the ignition of such mixtures over the full engine operation range is challenging, because of the lowered mixture reactivity and increased discrepancy of stoichiometry. In recent years, increasing research efforts have been spending on innovations of ignition technologies to tackle the challenges. In this paper, the directions of ignition improvement are highlighted based on the fundamental understanding of the ignition mechanisms. The working principles of the primary types of advanced ignition systems are introduced; and relevant engine and combustion vessel test results are reviewed. The ignition systems are categorized as: (1) high-energy spark ignition, (2) pulsed nanosecond discharge ignition, (3) radio-frequency plasma ignition, (4) laser-induced plasma ignition, and (5) pre-chamber ignition. The advanced ignition systems are commented, regarding the ignition effectiveness and the implementation challenges, according to the literatures and the extensive empirical work at the authors’ laboratory.

Analysis of experimental results with an active pre-chamber ultra-lean burn SI engine

2020 ◽  
pp. 146808742097454
Author(s):  
Christoph Müller ◽  
Stefan Pischinger ◽  
Sascha Tews ◽  
Andreas Müller ◽  
Knut Habermann
Keyword(s):  
Natural Gas ◽  
Fuel Consumption ◽  
Gasoline Engine ◽  
Combustion Process ◽  
Experimental Investigations ◽  
Major Step ◽  
Lean Burn ◽  
Hybrid Powertrain ◽  
Engine Operation ◽  
Gasoline Engines

To ensure that private cars can continue to be used in the future, they must become significantly more efficient and at the same time emit considerably less pollutants. In addition to pure electric drives, further optimized gasoline engines in hybrid powertrain configurations still offer major potentials in this respect. A major step toward increasing efficiency can be achieved by extremely lean burn combustion. If, in addition to low fuel consumption, this operation should also simultaneously reduce NOx raw emissions, lean-burn operation with relative air/fuel ratios of λ≥ 2 must be enabled in wide ranges of the engine operation map. Within the scope of this publication, results of experimental investigations with a lean burn pre-chamber ignition system applied to a small gasoline engine with 75 mm bore and 90.5 mm stroke are presented. In this context, the effects of the pre-chamber design on emissions and fuel consumption are examined. By comparing different pre-chamber enrichments with natural gas and conventional RON98 gasoline, it can be shown that with the direct liquid injection of gasoline into the pre-chamber similar good thermodynamic results as with natural gas can be achieved with the advantage of easier integration of a single fuel system. Due to its significantly improved lean burn capability with relative air/fuel rations of up to λ = 3, combined with low specific indicated NOx raw emissions of less than 0.1 g/kWh, the presented lean-burn combustion system offers excellent conditions for further efficiency improvements of electrified powertrains. WLTP cycle simulations based on measured engine maps for the developed combustion process resulted in a fuel consumption reduction of up to 10%. At the same time, NOx raw emissions below the Euro 6d limit of 60 mg/km can be achieved.

Diagnosis Research on Main Bearing Wear of Gasoline Engines in Mechanical Engineering

2013 ◽  
Vol 644 ◽  
pp. 304-307 ◽  
Author(s):  
Chang Shun Wang
Keyword(s):  
Gasoline Engine ◽  
Vibration Monitoring ◽  
Analysis Method ◽  
Characteristic Parameters ◽  
Main Bearing ◽  
Vibration Signals ◽  
Gasoline Engines ◽  
Test Spot ◽  
Monitoring Mechanism ◽  
Spectral Analysis Method

The different clearances of main bearing of previously designed on EQ6100 model gasoline engine is diagnosed by means of vibration monitoring mechanism. Breakdown signals of main test on different speed, clearance of main bearing, test spot and weather were analyzed by Spectral Analysis method and compared with normal and abnormal vibration signals. As a result, the characteristic parameters and the identifying methods of breakdown are given. In addition, the problems of fault detection are pointed out.

Tumble Flow Measurements Using Three Different Methods and Its Effects on Fuel Economy and Emissions

2006 ◽  
Author(s):  
Myoungjin Kim ◽  
Sihun Lee ◽  
Wootae Kim
Keyword(s):  
Fuel Economy ◽  
High Performance ◽  
Gasoline Engine ◽  
Exhaust Emissions ◽  
Combustion Stability ◽  
Lean Burn ◽  
Flow Measurements ◽  
Part Load ◽  
Gasoline Engines ◽  
Dynamometer Test

In-cylinder flows such as tumble and swirl have an important role on the engine combustion efficiencies and emission formations. In particular, the tumble flow, which is dominant in-cylinder flow in current high performance gasoline engines, has an important effect on the fuel consumptions and exhaust emissions under part load conditions. Therefore, it is important to know the effect of the tumble ratio on the part load performance and optimize the tumble ratio of a gasoline engine for better fuel economy and exhaust emissions. First step in optimizing a tumble flow is to measure a tumble ratio accurately. In this research the tumble flow was measured, compared and correlated using three different measurement methods: steady flow rig, 2-Dimensional PIV, and 3-Dimensional PTV. Engine dynamometer test was performed to find out the effect of the tumble ratio on the part load performance. Dynamometer test results of high tumble ratio engine showed faster combustion speed, retarded MBT timing, higher exhaust emissions, and a better lean burn combustion stability. Lean limit of the baseline engine was expanded from A/F=18:1 to A/F=21:1 by increasing a tumble ratio using MTV.

Optimization of Mode Switching Timing Control for a Lean-Burn Gasoline Engine With a Prototype Passive SCR System

2018 ◽  
Author(s):  
Dakota Strange ◽  
Pingen Chen ◽  
Vitaly Y. Prikhodko ◽  
James E. Parks
Keyword(s):  
Gasoline Engine ◽  
Nox Reduction ◽  
Cost Effective ◽  
Nox Storage ◽  
Mode Switching ◽  
Timing Control ◽  
Lean Burn ◽  
Gasoline Engines ◽  
Effective Manner ◽  
Passive Scr

Passive selective catalytic reduction (SCR) has emerged as a promising NOx reduction technology for highly-efficient lean-burn gasoline engines to meet stringent NOx emission regulation in a cost-effective manner. In this study, a prototype passive SCR which includes an upstream three-way catalyst (TWC) with added NOx storage component, and a downstream urealess SCR catalyst, was investigated. Engine experiments were conducted to investigate and quantify the dynamic NOx storage/release behaviors as well as dynamic NH3 generation behavior on the new TWC with added NOx storage component. Then, the lean/rich mode-switching timing control was optimized to minimize the fuel penalty associated with passive SCR operation. Simulation results show that, compared to the baseline mode-switching timing control, the optimized control can reduce the passive SCR-related fuel penalty by 6.7%. Such an optimized mode-switching timing control strategy is rather instrumental in realizing significant fuel efficiency benefits for lean-burn gasoline engines coupled with cost-effective passive SCR systems.

scholarly journals Direct Measurement of Ammonia Storage on Passive SCR Systems for Lean Gasoline NOx Reduction Using Radio Frequency Sensing

2019 ◽  
Author(s):  
Paul Ragaller ◽  
Josh Mandelbaum ◽  
Luc Lapenta ◽  
Alexander Sappok ◽  
Josh Pihl ◽  
...  
Keyword(s):  
Radio Frequency ◽  
Real Time ◽  
Gasoline Engine ◽  
Nox Reduction ◽  
Practical Implementation ◽  
Engine Operation ◽  
Ammonia Storage ◽  
Scr System ◽  
Lean Gasoline ◽  
Passive Scr

Abstract Lean gasoline engine operation provides clear efficiency benefits relative to conventional stoichiometric combustion approaches. One of the key hurdles to the widespread, practical implementation of lean gasoline combustion remains the challenge of lean NOx control. One of the potential approaches for controlling NOx emission from lean gasoline engines is the so-called passive selective catalytic reduction (SCR) system. In such systems, periods of rich operation generate ammonia over a three-way catalyst (TWC), which is then adsorbed on the downstream SCR and consumed during lean operation. Brief periods of rich operation must occur in response to the depletion of stored ammonia on the SCR, which requires reliable measurements of the SCR ammonia inventory. Presently, lean exhaust system controls rely on a variety of gas sensors mounted up- and downstream of the catalysts, and which only provide an indirect inference of the operation state. In this study, a radio frequency (RF) sensor was used to provide a direction measurement of the amount of ammonia adsorbed on the SCR in real-time. The RF sensor was calibrated and deployed on a BMW N43B20 4-cylinder lean gasoline engine equipped with a passive SCR system. Brief periods of rich operation performed at lambda values between 0.98 and 0.99 generated the ammonia, subsequently stored on the SCR for consumption during periods of lean operation. The experiments compared real-time measurements of SCR ammonia inventory from the RF sensor with estimates of ammonia coverage derived from exhaust gas composition measurements upstream and downstream of the catalyst. The results showed a high degree of correlation between the RF measurements and SCR ammonia storage inventory, and demonstrated NOx conversion efficiencies above 98%, confirming the feasibility of the concept. Relative to stoichiometric operation, lean-gasoline operation resulted in fuel efficiency gains of up to 10%, which may be further improved through direct feedback control from the RF sensor to optimize lean–rich cycling based on actual, measured SCR ammonia levels.

scholarly journals Exhaust emission from a vehicle engine operating in dynamic states and conditions corresponding to real driving

2019 ◽  
Vol 178 (3) ◽  
pp. 99-105
Author(s):  
Monika ANDRYCH-ZALEWSKA ◽  
Zdzisław CHŁOPEK ◽  
Jerzy MERKISZ ◽  
Jacek PIELECHA
Keyword(s):  
Rotational Speed ◽  
Time Derivative ◽  
Exhaust Emission ◽  
Test Results ◽  
Engine Operation ◽  
Vehicle Engine ◽  
University Of Technology ◽  
The Time Domain ◽  
Speed Characteristic ◽  
Dynamic States

The article presents the exhaust emission results from a diesel engine in dynamic states of engine operation in the driving tests: NEDC (New European Driving Cycle) and Malta test, developed at the Poznan University of Technology. The NEDC and Malta tests were carried out as simulations on the engine test bench mimicking the driving tests conditions. The test results of the emission of carbon monoxide, hydrocarbons and nitrogen oxides obtained in each of the tests were presented. The dynamic states have been classified de-pending on the time derivative value of the torque and engine rotational speed. Both the positive and negative as well as zero time deriv-ative values of torque and rotational speed were considered. Therefore, overall six types of dynamic states were analyzed. A high sensi-tivity of exhaust emission to various types of dynamic states was found. The exhaust emission sensitivity to dynamic states in the Malta test was found to be higher than for the NEDC test, although these tests have similar properties (average rotational speed and average torque). This is due to the fact that the NEDC test is created on the basis of the similarity of zero-dimensional characteristics of the cars speed characteristic, whereas the Malta test was designed in accordance with the principle of faithful representation in the time domain of the NEDC speed curve.

scholarly journals Identification of Ru/Ceria Among Single Atom Ceria Catalysts as a Stable and Superior Material for Abatement of Diesel and Gasoline Engine Pollutants

2020 ◽  
Author(s):  
Konstantin Khivantsev ◽  
Nicholas R. Jaegers ◽  
Libor Kovarik ◽  
Jinshu Tian ◽  
Xavier Isidro Pereira Hernandez ◽  
...  
Keyword(s):  
Gasoline Engine ◽  
No Oxidation ◽  
Oxidation Catalyst ◽  
Single Atom ◽  
Hydrothermal Aging ◽  
Gasoline Engines ◽  
Nox Adsorption ◽  
Ceria Catalysts ◽  
Better Than ◽  
Three Way Catalysis

Atomically dispersed transition metals (Ru, Pd and Pt) have been prepared on CeO<sub>2</sub> and evaluated for NOx/CO abatement applications for diesel and gasoline engines, such as low temperature passive NOx adsorption (PNA), NO and CO oxidation, and three-way-catalysis (TWC). 0.5 wt% Ru/CeO<sub>2</sub> catalyst (Ru is ~27 and ~7 times cheaper than Rh and Pd) shows remarkable PNA performance, better than 1 wt% Pd/Zeolite: it achieves 100% removal of NOx during vehicle cold start. FTIR measurements reveal the formation of stable Ru(NO) complexes as well spill-over of NO to CeO<sub>2</sub> surface via the Ru-O-Ce shuttle, explaining high NO storage. Notably, Ru/ceria survives hydrothermal aging at 750 ⁰C without loss of PNA capacity. It is also a robust NO oxidation catalyst, considerably more active than Pt or Pd/CeO<sub>2</sub>. Expanding the repertoire of Ru/CeO<sub>2</sub> catalytic applications, we further find 0.1 and 0.5 wt% Ru/CeO<sub>2</sub> to be excellent TWC catalysts, rivaling best single-atom Rh supported materials. Our study pushes the frontier of precious metal atom economy for environmental catalysis from uber expensive Rh/Pd/Pt to more sustainable cheaper Ru and highlights the utility of single-atom catalysts for industrially relevant applications.

Sign in / Sign up

Export Citation Format

Share Document