scholarly journals Analisis Perbandingan Kekerasan Beberapa Merk Katup Sepeda Motor Matic

2020 ◽  
Vol 1 (2) ◽  
pp. 75-84
Author(s):  
Arif Rahmat Ali ◽  
Hasan Maksum ◽  
Donny Fernandez
Keyword(s):  
Comparative Study ◽  
Exhaust Valve ◽  
Intake Valve

This article discusses a comparison of the hardness of several valve brands for automatic motorbikes. This research used comparative study method. The motorbike used was the Honda VARIO 110 cc motorcycle. Meanwhile, the valves used and compared are Honda Genuine Parts and several brands of aftermarket valves. The results showed that the hardest intake valve head was the Genuine Valve with 61.7 HRA and the hardest exhaust valve head was the NPP with 58.9 HRA. Artikel ini membahas mengenai perbandingan kekerasan beberapa merek katup untuk sepeda motor matic. Penelitian ini menggunakan metode penelitian komparatif. Sepeda motor yang digunakan adalah Sepeda Motor Honda VARIO 110 cc. Sementara untuk katup yang digunakan dan diperbandingkan adalah Honda Genuine Parts dan beberapa merk Katup aftermarket. Hasil penelitian menunjukkan payung katup masuk yang paling keras yaitu payung katup Original 61,7 HRA dan payung katup buang yang paling keras yaitu payung katup NPP 58,9 HRA.

Diesel Engine Performance Improvement for Constant Speed Application Using CFD

2017 ◽  
Author(s):  
Balasaheb S. Dahifale ◽  
Anand S. Patil
Keyword(s):  
Combustion Chamber ◽  
Fuel Consumption ◽  
Performance Improvement ◽  
Test Data ◽  
Engine Performance ◽  
Exhaust Valve ◽  
Fine Tuning ◽  
Intake Valve ◽  
Valve Seat ◽  
Load Conditions

The detailed investigation of flow behavior inside the combustion chamber and performance of engine is most challenging problem due to constraints in Experimental Data collection during testing; However, Experimental testing is essential for establishment of correlation with CFD Predictions. Hence, the baseline engine was tested at different load conditions and validated with CFD results, before it was optimized for performance improvement. The objective of the CFD Prediction was not only to optimize performance (Fuel Efficiency, Power, Torque, etc.) & Emissions Reduction, but also to assess feasibility of Performance Upgrade Potential. In the present CFD study, surface mesh and domain was prepared for the flame face, intake valve, intake valve seat, exhaust valve, exhaust valve seat and liner for closed volume cycle, between IVC and EVO using CFD code VECTIS. Finally simulations for three different load conditions were conducted using VECTIS solver. Initially, in-cylinder pressure vis a vis crank angle prediction was carried out for 100%, 75% and 50% load conditions. Then the fine tuning of (P-ϴ) diagram for different load conditions was conducted by varying different combustion parameters. Further, the engine performance validation was carried out for rated and part load conditions in terms of, IMEP, BMEP, break specific fuel consumption and power output, while NOx mass fractions were used to convert the NOx to g/kWh for comparison of emission levels with the test data. Finally optimized re-entrant combustion chamber and modified valve timing with optimum fuel injection system simulation was carried out to achieve target performance with reduced fuel consumption. A 3D CFD result showed reduction in BSFC and was in close agreement with the test data.

Design and Dynamic Analysis of an Innovative Axial Shift Valvetrain System (ASVS) for Variable Stroke Engine

2021 ◽  
pp. 146808742110653
Author(s):  
Jingchen Cui ◽  
Liping Chen ◽  
Wuqiang Long ◽  
Xiangyu Meng ◽  
Bo Li ◽  
...  
Keyword(s):  
Contact Force ◽  
Engine Speed ◽  
Exhaust Valve ◽  
Valve Lift ◽  
Intake Valve ◽  
Power Performance ◽  
Working Cycle ◽  
Valve Motion ◽  
Axial Shift ◽  
Stroke Engine

A variable valvetrain system is the key part of the variable stroke engine (VSE), which could achieve higher power performance and low-speed torque. An innovative axial shift valvetrain system (ASVS) was put forward to meet the air-charging requirements of a 2/4-stroke engine and complete a changeover within one working cycle. Two sets of intake and exhaust cam profiles for both intake and exhaust sides in the 2/4-stoke mode were designed for 2/4-stoke modes. Furthermore, a simulation model based on ADAMS was established to evaluate the dynamic valve motion and the contact force at different engine speeds. The dynamic simulation results show that the valve motion characteristics meet the challenges at the target engine speed of 3000 r/min. In two-stroke mode, the maximum intake valve lift could achieve 7.3 mm within 78°CaA, and the maximum exhaust valve lift could achieve 7.5 within 82°CaA on the exhaust side. In four-stroke mode, the maximum intake valve lift can achieve 8.8 mm within 140°CaA, and the maximum exhaust valve lift can achieve 8.4 mm within 140°CaA. The valve seating speeds are less than 0.3 m/s in both modes, and the fullness coefficients are more than 0.5 and 0.6 in the 2-stroke and 4-stroke mode, respectively. At the engine speed of 3000 r/min, the contact force on each component is acceptable, and the stress between cam and roller can meet the material requirement.

Energy Efficiency Analysis of Piston Type Air Compressor

2014 ◽  
Vol 981 ◽  
pp. 769-773
Author(s):  
Su Lu Zheng ◽  
Yun Yan Mao ◽  
Xiang Ping Wang ◽  
Zhi Yun Zheng ◽  
Shen Xi He ◽  
...  
Keyword(s):  
Energy Efficiency ◽  
Rotational Speed ◽  
Exhaust Valve ◽  
Valve Lift ◽  
Optimal Conditions ◽  
Intake Valve ◽  
Air Compressor ◽  
Relationship Of ◽  
The Relationship ◽  
Energy Efficiency Analysis

In the paper,the relationship of the energy efficiency and its impact factor such as intake valve lift ,exhaust valve lift, clearance volume and rotational speed has been researched and the optimal conditions of the air compressor running was found . By adjusting the parameters of intake valve lift, exhaust valve lift, clearance volume and rotational speed, the total energy of a W-1.6/5 compressor could be reduced by 10.9%.

Application of Variable Valve Actuation Strategies and Direct Gasoline Injection Schemes to Reduce Combustion Harshness and Emissions of Boosted HCCI Engine

2019 ◽  
Vol 141 (7) ◽  
Author(s):  
Jacek Hunicz ◽  
Maciej Mikulski
Keyword(s):  
Pressure Rise ◽  
Operating Conditions ◽  
Exhaust Valve ◽  
Boost Pressure ◽  
Pressure Reduction ◽  
Intake Valve ◽  
Valve Timing ◽  
Hcci Engine ◽  
Auto Ignition ◽  
The Impact

The present study investigates various measures to reduce pressure rise rates (PRRs) in a residual-affected homogeneous charge compression ignition (HCCI) engine. At the same time, the impact of those measures on efficiency and emissions is assessed. Experimental research was performed on a single cylinder engine equipped with a fully flexible valve train mechanism and direct gasoline injection. The HCCI combustion mode with exhaust gas trapping was realized using negative valve overlap (NVO) and fuel reforming, achieved via the injection of a portion of fuel during exhaust recompression. Three measures are investigated for the PRR control under the same reference operating conditions, namely: (i) variable intake and exhaust valve timing, (ii) boost pressure adjustment, and (iii) split fuel injection to control the amount of fuel injected for reforming. Variable exhaust valve timing enabled control of the amount of trapped residuals, and thus of the compression temperature. The reduction in the amount of trapped residuals, at elevated engine load, delays auto-ignition, which results in a simultaneous reduction of pressure rise rates and nitrogen oxides emissions. The effects of intake valve timing are much more complex because they include the variability in the amount of intake air, the thermodynamic compression ratio, as well as the in-cylinder fluid flow. It was found, however, that both early and late intake valve openings (IVOs) delay auto-ignition and prolong combustion. Additionally, the reduction of the amount of fuel injected during exhaust recompression further delays combustion and reduces combustion rates. Intake pressure reduction has by far the largest effect on peak pressure reduction yet is connected with excessive NOX emissions. The research successfully identifies air-path and injection techniques, which allow for the control of combustion rates and emissions under elevated load regime.

scholarly journals The effect of bowl-in-piston geometry layout on fluid flow pattern

2011 ◽  
Vol 15 (3) ◽  
pp. 817-832 ◽  
Author(s):  
Zoran Jovanovic ◽  
Zlatomir Zivanovic ◽  
Zeljko Sakota ◽  
Miroljub Tomic ◽  
Velimir Petrovic
Keyword(s):  
Fluid Flow ◽  
Flow Pattern ◽  
Moving Objects ◽  
Three Dimensional ◽  
Exhaust Valve ◽  
Intake Valve ◽  
Combustion Chambers ◽  
Arbitrary Geometry ◽  
One Dimensional ◽  
Close Proximity

In this paper some results concerning the evolution of 3D fluid flow pattern through all four strokes in combustion chambers with entirely different bowl-in-piston geometry layouts ranging from ?omega? to ?simple cylinder? were presented. All combustion chambers i.e. those with ?omega? bowls, with different profiles, and those with ?cylinder? bowls, with different squish area ranging from 44% to 62%, were with flat head, vertical valves and identical elevation of intake and exhaust ports. A bunch of results emerged by dint of multidimensional modeling of nonreactive fluid flow in arbitrary geometry with moving objects and boundaries. The fluid flow pattern during induction and compression in all cases was extremely complicated and entirely three-dimensional. It should be noted that significant differences due to geometry of the bowl were encountered only in the vicinity of TDC. Namely, in the case of ?omega? bowl all three types of organized macro flows were observed while in the case of ?cylinder? bowl no circumferential velocity was registered at all. On the contrary, in the case of ?cylinder? bowl some interesting results concerning reverse tumble and its center of rotation shifting from exhaust valve zone to intake valve zone during induction stroke and vice-verse from intake valve zone to exhaust valve zone during compression were observed while in the case of ?omega? bowl no such a displacement was legible. During expansion the fluid flow pattern is fully controlled by piston motion and during exhaust it is mainly one-dimensional, except in the close proximity of exhaust valve. For that reason it is not affected by the geometry of the bowl.

Application of Variable Valve Actuation Strategies and Direct Gasoline Injection Schemes to Reduce Combustion Harshness and Emissions of Boosted HCCI Engine

2018 ◽  
Author(s):  
Jacek Hunicz ◽  
Maciej Mikulski
Keyword(s):  
Pressure Rise ◽  
Operating Conditions ◽  
Exhaust Valve ◽  
Boost Pressure ◽  
Pressure Reduction ◽  
Intake Valve ◽  
Valve Timing ◽  
Hcci Engine ◽  
Auto Ignition ◽  
The Impact

One of the pending issues regarding Homogeneous Charge Compression Ignition (HCCI) engines is high load operation limit constrained by excessive pressure rise rates (PRRs). The present study investigates various measures to reduce combustion harness in a residual-affected HCCI engine. At the same time, the impact of those measures on efficiency and emissions is assessed. Experimental research was performed on a single cylinder engine equipped with a fully-flexible valvetrain mechanism and direct gasoline injection. The HCCI combustion mode with exhaust gas trapping was realized using negative valve overlap and fuel reforming, achieved via the injection of a portion of fuel during exhaust re-compression. Three measures are investigated for the PRR control under the same reference operating conditions, namely: (i) variable intake and exhaust valve timing, (ii) boost pressure adjustment and (iii) split fuel injection to control the amount of fuel injected for reforming. Variable exhaust valve timing enabled control of the amount of trapped residuals, and thus of the compression temperature. The reduction in the amount of trapped residuals, at elevated engine load, delays auto-ignition, which results in a simultaneous reduction of pressure rise rates and nitrogen oxides emissions. The effects of intake valve timing are much more complex, because they include the variability in the amount of intake air, the thermodynamic compression ratio as well as the in-cylinder fluid flow. It was found, however, that both early and late intake valve openings delay auto-ignition and prolong combustion. Additionally, the reduction of the amount of fuel injected during exhaust re-compression further delays combustion and reduces combustion rates. Intake pressure reduction has by far the largest effect on peak pressure reduction yet is connected with excessive NOx emissions. The research successfully identifies air-path and injection techniques, which allow for the control of combustion rates and emissions under elevated load regime, thus shorting the gap towards the real-world application of HCCI concepts.

scholarly journals Effect of Valve Timing and Excess Air Ratio on Torque in Hydrogen-Fueled Internal Combustion Engine for UAV

Energies ◽  
2019 ◽  
Vol 12 (5) ◽  
pp. 771 ◽  
Author(s):  
Cheolwoong Park ◽  
Wonah Park ◽  
Yongrae Kim ◽  
Young Choi ◽  
Byeungjun Lim
Keyword(s):  
Gasoline Engine ◽  
Combustion Engine ◽  
Control Unit ◽  
Operating Conditions ◽  
Exhaust Valve ◽  
Airflow Rate ◽  
Intake Valve ◽  
Hydrogen Fuel ◽  
Excess Air ◽  
Valve Opening

In this study, in order to convert a 2.4 L reciprocating gasoline engine into a hydrogen engine an experimental device for supplying hydrogen fuel was installed. Additionally, an injector that is capable of supplying the hydrogen fuel was installed. The basic combustion characteristics, including torque, were investigated by driving the engine with a universal engine control unit. To achieve stable combustion and maximize output, the intake and exhaust valve opening times were changed and the excess air ratio of the mixture was controlled. The changes in the torque, excess air ratio, hydrogen fuel, and intake airflow rate, were compared under low engine speed and high load (wide open throttle) operating conditions without throttling. As the intake valve opening time advanced at a certain excess air ratio, the intake air amount and torque increased. When the opening time of the exhaust valve was retarded, the intake airflow rate and torque decreased. The torque and thermal efficiency decreased when the opening time of the intake and exhaust valve advanced excessively. The change of the mixture condition’s excess air ratio did not influence the tendency of the torque variation when the exhaust valve opening time and torque increased, and when the mixture became richer and the intake valve opening time was fixed. Under a condition that was more retarded than the 332 CAD condition, the torque decreased by about 2 Nm with the 5 CAD of intake valve opening time retards. The maximum torque of 138.1 Nm was obtained at an optimized intake and the exhaust valve opening time was 327 crank angle degree (CAD) and 161 CAD, respectively, when the excess air ratio was 1.14 and the backfire was suppressed. Backfire occurred because of the temperature increase in the combustion chamber rather than because of the change in the fuel distribution under the rich mixture condition, where the other combustion control factors were constantly fixed from a three-dimensional (3D) computational fluid dynamics (CFD) code simulation.

Diesel engine optimization and exhaust thermal management by means of variable valve train strategies

2020 ◽  
pp. 146808741989480 ◽  
Author(s):  
Francisco J Arnau ◽  
Jaime Martín ◽  
Benjamín Pla ◽  
Ángel Auñón
Keyword(s):  
Exhaust Valve ◽  
Pollutant Emission ◽  
Variable Valve Timing ◽  
Intake Valve ◽  
Valve Timing ◽  
Test Cycle ◽  
Trade Off ◽  
Warm Up ◽  
Valve Opening ◽  
Variable Valve

Due to the need to achieve a fast warm-up of the after-treatment system in order to fulfill the pollutant emission regulations, a growing interest has arisen to adopt variable valve timing technology for automotive engines. Several variable valve timing strategies can be used to achieve an increment in the after-treatment upstream temperature by increasing the residual gas amount. In this study, a one-dimensional gas dynamics engine model has been used to carry out a simulation study comparing several exhaust variable valve actuation strategies. A steady-state analysis has been done in order to evaluate the potential of the different strategies at different operating points. Finally, the effect on the after-treatment warm-up, fuel economy and pollutant emission levels was evaluated over the worldwide harmonized light vehicles test cycle. As a conclusion, the combination of an advanced exhaust (early exhaust valve opening and early exhaust valve closing) and a delayed intake (late intake valve opening and late intake valve closing) presented the best trade-off between exhaust temperature increment and fuel consumption, which achieved a mean temperature increment during low-speed phase of the worldwide harmonized light vehicles test cycle of 27 °C with a fuel penalty of 6%. The exhaust valve re-opening technique offers a worse trade-off. However, the exhaust valve re-opening leads to lower nitrogen oxide (29% less) and carbon monoxide (11% less) pollutant emissions.

Author response for "Laminar distribution of cortical projection neurons to the pulvinar: A comparative study in cats and mice"

2020 ◽  
Author(s):  
Bruno Oliveira Ferreira de Souza ◽  
Éve‐Marie Frigon ◽  
Robert Tremblay‐Laliberté ◽  
Christian Casanova ◽  
Denis Boire
Keyword(s):  
Comparative Study ◽  
Author Response ◽  
Projection Neurons ◽  
Cortical Projection ◽  
Laminar Distribution
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