Performance Tuning of an IC Engine Based on Pressure Wave Propagation With a Continuously Variable Exhaust Runner Length and Exhaust Valve Timing System

2017 ◽  
Author(s):  
V. Gajula ◽  
S. Bari
Keyword(s):  
Pressure Wave ◽  
Engine Performance ◽  
Exhaust Valve ◽  
Performance Tuning ◽  
Valve Timing ◽  
Ic Engine ◽  
Scavenging Effect ◽  
Varying Length ◽  
Valve Opening ◽  
Positive Effect

The momentum of exhaust gas flowing out of the valve creates a pressure wave which can have a positive effect on the evacuation of gases. This concept is known as wave tuning, utilizes the sub-atmospheric pressure waves in the runner to evacuate more exhaust gases. When tuned precisely by varying length and/or exhaust valve timing in such a way that the wave returns in accordance to the exhaust valve opening, it creates a scavenging effect and this improves the engine performance. In this research both exhaust runner length and valve duration have been changed to arrive the sub-atmospheric wave at exhaust valve to improve the performance of the engine using Ricardo WAVE software. It was found that varying the exhaust valve timing managed to improve the torque by 1–3% at different rpm. However, varying both length and timing improved the toque 7–10% at lower speed and 3–6% at higher rpm.

scholarly journals Engine Manifold Wave Action under Variable Stroke Length

2017 ◽  
Vol 11 (8) ◽  
pp. 79
Author(s):  
Jehad Ahmad Yamin
Keyword(s):  
Diesel Engine ◽  
Pressure Wave ◽  
Direct Injection ◽  
Engine Performance ◽  
Wave Action ◽  
Pressure Waves ◽  
Valve Timing ◽  
Stroke Length ◽  
Piston Bowl ◽  
Wide Range

A theoretical investigation on the pressure wave action of the manifolds of a four-stroke, direct injection (hereinafter referred to as DI), water-cooled, 4-stroke, diesel engine with variable stroke length was carried out.  The study was conducted over wide range of speeds (1000 - 3000 RPM at an increment of 500 RPM) and stroke lengths (130 mm to 210 mm at an increment of 20mm). The compression ratio was kept constant by adjusting the piston bowl volume. The study showed that shorter stroke lengths created favorable pressure waves in both inlet and exhaust manifolds at lower speeds, which resulted in improved engine volumetric and thermal efficiencies. At higher speeds, the larger strokes were favorable, however, due to less time available for the suction and exhaust strokes to be executed, the efficiencies were low. Advancing valve timing was one factor that improved the engine performance with larger stroke lengths.

scholarly journals PENCAPAIAN PERFORMA PADA KATUP VARIABEL TIMING FIXED TIMING UNTUK MESIN YANG OPTIMAL

2012 ◽  
Vol 11 (1) ◽  
pp. 68
Author(s):  
KETUT ASTAWA
Keyword(s):  
Engine Performance ◽  
Variable Valve Timing ◽  
Intake Valve ◽  
Valve Timing ◽  
Static Test ◽  
Load Transmission ◽  
Valve Opening ◽  
Efficient Machine ◽  
Hc Emissions ◽  
Variable Valve

Problems will be discussed in this research is how differences in exhaust emissions generatedby engine with variable valve timing and valve timing on a fixed volume of motor vehiclecylinder 1300 cc. Variable valve timing technology, which is set when opening and closingthe intake valve (intake valve) electronic fuel according to engine conditions. This will makemixing air and fuel that enters into an efficient machine that will produce great power, fueleconomy and low emissions. Research emissions (CO, CO2, HC, O2) was performedwith dynamictesting, where the vehicle in a state of the load lifted and given transmission. Unlikethe testing generally performed with a static test, in which the vehicle is at rest and without aload. This test is performed to determine how the condition of exhaust gases when the vehicledynamic (analogous to the vehicle running). In general, machines with variable valve timingto produce better emissions than engines with fixed valve timing. The higher the spin machineand load transmission system will result in CO and HC emissions are decreased and O2 andCO2 increased. Engine with variable valve timing control the suction valve opening times toachieve optimum engine performance at various driving conditions. And set out the engineoutput as needed.

scholarly journals Pengaruh perubahan sudut camshaft terhadap performa mesin sepeda motor sebagai upaya efisiensi energi

2020 ◽  
Vol 9 (1) ◽  
Author(s):  
Lukito Dwi Yuono ◽  
Eko Budiyanto
Keyword(s):  
Combustion Chamber ◽  
Fuel Consumption ◽  
Engine Performance ◽  
Exhaust Valve ◽  
Compression Pressure ◽  
A Value ◽  
Valve Opening ◽  
Motorcycle Engine

The role of the camshaft (noken as) is very important, including determining the time to open the valve, regulating the length of the valve opening duration, determining the overlap inlet and exhaust valve duration, as well as being a major component of the engine's working system. Modification of the camshaft angle is expected to be able to increase the efficiency of the combustion of fuel entering the combustion chamber and increase compression pressure in the combustion chamber so that it can improve volume quality of fuel entering the combustion chamber and can provide greater power to the engine rotation when in use. The purpose of this study was to determine the effect of camshaft angle changes on motorcycle engine performance and determine the effect of the camshaft duration on fuel consumption. The method that will be used in this research is to provide variations in angular changes on the camshaft of 20, 40, 60.Then test the dyno test on each variable. The result, the highest torque is the camshaft 40 variation with a value of 8.25 Nm. The highest power is in variation 40 with the highest number of 8.76 PS. Acceleration with the fastest time is obtained in camshaft 40 variations with a time of 14.2 seconds at a speed of 100 km/h. As well as the most efficient fuel consumption is at variation 20 with 150 ml fuel consumption.Keywords: Angle, camshaft, and engine performance.

Combined Effects of Variable Intake Manifold Length, Variable Valve Timing and Duration on the Performance of an Internal Combustion Engine

2017 ◽  
Author(s):  
P. Sawant ◽  
S. Bari
Keyword(s):  
Combustion Engine ◽  
Engine Performance ◽  
Internal Combustion ◽  
Intake Manifold ◽  
Combined Effects ◽  
Performance Parameters ◽  
Intake Valve ◽  
Valve Timing ◽  
Ic Engine ◽  
Speed Range

Naturally aspirated internal combustion (IC) engines with a fixed intake assembly are generally tuned to produce an induction boost at a single engine speed by capitalizing the induction pressure waves only over a narrow speed range. This paper investigates the individual and combined effects of varying intake runner length and intake valve timing on the performance parameters of an IC engine at engine speeds from 3000 rpm to 9000 rpm. The 1-D model of the KTM SI engine built for simulations in Ricardo Wave software is validated with 98% accuracy against experimental test results. The performance parameters thus obtained, as a combined effect, show an average improvement of 7.02% throughout the engine’s speed range. With the co-existence of variable length intake runners and variable intake valve opening timing, the required number of variations to boost the engine performance are found to be reduced making variable intake assembly more feasible.

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.

Implementing variable valve actuation on a diesel engine at high-speed idle operation for improved aftertreatment warm-up

2019 ◽  
Vol 21 (7) ◽  
pp. 1134-1146
Author(s):  
Kalen R Vos ◽  
Gregory M Shaver ◽  
Mrunal C Joshi ◽  
James McCarthy
Keyword(s):  
Particulate Matter ◽  
High Speed ◽  
Exhaust Valve ◽  
Exhaust Gas ◽  
Warm Up ◽  
Aftertreatment System ◽  
Idle Speed ◽  
Variable Valve Actuation ◽  
Brake Mean Effective Pressure ◽  
Valve Opening

Aftertreatment thermal management is critical for regulating emissions in modern diesel engines. Elevated engine-out temperatures and mass flows are effective at increasing the temperature of an aftertreatment system to enable efficient emission reduction. In this effort, experiments and analysis demonstrated that increasing the idle speed, while maintaining the same idle load, enables improved aftertreatment “warm-up” performance with engine-out NOx and particulate matter levels no higher than a state-of-the-art thermal calibration at conventional idle operation (800 rpm and 1.3 bar brake mean effective pressure). Elevated idle speeds of 1000 and 1200 rpm, compared to conventional idle at 800 rpm, realized 31%–51% increase in exhaust flow and 25 °C–40 °C increase in engine-out temperature, respectively. This study also demonstrated additional engine-out temperature benefits at all three idle speeds considered (800, 1000, and 1200 rpm, without compromising the exhaust flow rates or emissions, by modulating the exhaust valve opening timing. Early exhaust valve opening realizes up to ~51% increase in exhaust flow and 50 °C increase in engine-out temperature relative to conventional idle operation by forcing the engine to work harder via an early blowdown of the exhaust gas. This early blowdown of exhaust gas also reduces the time available for particulate matter oxidization, effectively limiting the ability to elevate engine-out temperatures for the early exhaust valve opening strategy. Alternatively, late exhaust valve opening realizes up to ~51% increase in exhaust flow and 91 °C increase in engine-out temperature relative to conventional idle operation by forcing the engine to work harder to pump in-cylinder gases across a smaller exhaust valve opening. In short, this study demonstrates how increased idle speeds, and exhaust valve opening modulation, individually or combined, can be used to significantly increase the “warm-up” rate of an aftertreatment system.

Ethers and esters as alternative fuels for internal combustion engine: A review

2021 ◽  
pp. 146808742110464
Author(s):  
Yang Hua
Keyword(s):  
Alternative Fuels ◽  
Combustion Engine ◽  
Combustion Process ◽  
Pressure Rise ◽  
Engine Performance ◽  
Internal Combustion ◽  
Operating Conditions ◽  
Future Research ◽  
Particulate Emissions ◽  
Ic Engine

Ether and ester fuels can work in the existing internal combustion (IC) engine with some important advantages. This work comprehensively reviews and summarizes the literatures on ether fuels represented by DME, DEE, DBE, DGM, and DMM, and ester fuels represented by DMC and biodiesel from three aspects of properties, production and engine application, so as to prove their feasibility and prospects as alternative fuels for compression ignition (CI) and spark ignition (SI) engines. These studies cover the effects of ether and ester fuels applied in the form of single fuel, mixed fuel, dual-fuel, and multi-fuel on engine performance, combustion and emission characteristics. The evaluation indexes mainly include torque, power, BTE, BSFC, ignition delay, heat release rate, pressure rise rate, combustion duration, exhaust gas temperature, CO, HC, NOx, PM, and smoke. The results show that ethers and esters have varying degrees of impact on engine performance, combustion and emissions. They can basically improve the thermal efficiency of the engine and reduce particulate emissions, but their effects on power, fuel consumption, combustion process, and CO, HC, and NOx emissions are uncertain, which is due to the coupling of operating conditions, fuel molecular structure, in-cylinder environment and application methods. By changing the injection strategy, adjusting the EGR rate, adopting a new combustion mode, adding improvers or synergizing multiple fuels, adverse effects can be avoided and the benefits of oxygenated fuel can be maximized. Finally, some challenges faced by alternative fuels and future research directions are analyzed.

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