Improving working cycle parameters of six-stroke diesel engine by optimizing take-off angle of the intake valve to the bottom dead center at the intake stroke

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.

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NUMERICAL INVESTIGATION OF THE EFFECTS OF INTAKE VALVE GEOMETRY ON AIR FLOW DURING INTAKE STROKE

International Journal of Energy for a Clean Environment ◽

10.1615/interjenercleanenv.2021037511 ◽

2021 ◽

Author(s):

Burak Şeremet ◽

Nureddin Dinler

Keyword(s):

Numerical Investigation ◽

Air Flow ◽

Intake Valve ◽

Intake Stroke

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Influence of parameters and location of the tumble inlet porton air charging in the diesel cylinder

E3S Web of Conferences ◽

10.1051/e3sconf/201913501083 ◽

2019 ◽

Vol 135 ◽

pp. 01083 ◽

Cited By ~ 23

Author(s):

Besarion Meskhi ◽

Boris Golev ◽

Victor Efros ◽

Dmitriy Rudoy ◽

Anastasiya Olshevskaya ◽

...

Keyword(s):

Combustion Chamber ◽

Cross Section ◽

Individual Factors ◽

Time Of Arrival ◽

Intake Valve ◽

Working Cycle ◽

Dynamic Loadings ◽

Diesel Cylinder ◽

The Impact ◽

Fresh Charge

The calculation of the actual working cycle processes allows to determine with satisfactory accuracy the value of the main parameters of the newly developed engine for any given conditions of its operation, to assess the impact of individual factors on the processes and the performance of the cycle as a whole. Thus establish character of change of pressure and temperature in each process, define the sizes of the engine, and also solve questions of increase of its reliability taking into account the received settlement thermal and dynamic loadings. Pre-intake begins at the time of opening the inlet and ends at the time of arrival of the piston in the TDC. The mixture or air does not enter the cylinder during preheating, as the volume of the cylinder decreases. However, the pre-opening of the intake valve allows you to create a sufficient cross-section to the beginning of the receipt of fresh charge in the cylinder and, therefore, leads to an improvement in the filling of the cylinders. In addition, due to the delay in closing the exhaust valve, the purge of the combustion chamber from residual gases is improved.

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Repeatability of High-Pressure Measurement in a Diesel Engine Test Bed

Sensors ◽

10.3390/s20123478 ◽

2020 ◽

Vol 20 (12) ◽

pp. 3478 ◽

Cited By ~ 1

Author(s):

Tomasz Skrzek ◽

Mirosław Rucki ◽

Krzysztof Górski ◽

Jonas Matijošius ◽

Dalibor Barta ◽

...

Keyword(s):

Diesel Engine ◽

Pressure Measurement ◽

Ignition Process ◽

Engine Test ◽

Cylinder Pressure ◽

Test Bed ◽

Working Cycle ◽

Crank Angle ◽

Maximal Pressure ◽

Measured Pressure

This paper addresses the issue of metrological accuracy of instantaneous in-cylinder pressure measurement in a diesel engine test bed. In studies, the central unit has been the single-cylinder AVL 5402 engine. The pressure measurement was performed with a sensor designed for thermodynamic analysis, and the results were related to the crank angle, where two rotations corresponding to the four-stroke working cycle were denoted as angles between −360° and +360°. The novelty of this paper is the proposition of how to perform a type A uncertainty estimation of the in-cylinder pressure measurement and to assess its repeatability. It was demonstrated that repeatability of the measurement during the ignition process was difficult to estimate because of the phenomena that cannot ensure the repeatability conditions. To solve the problem, two methods were proposed. In one method, the pressure was measured in the subsequent cycles immediately after the ignition was turned off, and in another method, the engine was driven by a starter. The latter method provided maximal pressure values much lower than during usual tests. The obtained repeatability of measured pressure was %EV = 0.4%, which proved high capability of the evaluated measurement system.

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Control-oriented PCCI combustion timing model for a diesel engine utilizing flexible intake valve modulation and high EGR levels

2012 American Control Conference (ACC) ◽

10.1109/acc.2012.6314776 ◽

2012 ◽

Cited By ~ 5

Author(s):

D. G. Van Alstine ◽

L. E. Kocher ◽

E. Koeberlein ◽

K. Stricker ◽

G. M. Shaver

Keyword(s):

Diesel Engine ◽

Intake Valve ◽

Timing Model

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Study on Optimization of the Diesel Engine Controlling Parameters Based on Genetic Algorithm

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.253-255.2125 ◽

2012 ◽

Vol 253-255 ◽

pp. 2125-2129

Author(s):

Qing Guo Luo ◽

Hong Bin Liu ◽

Qiang Ma

Keyword(s):

Genetic Algorithm ◽

Diesel Engine ◽

Economic Efficiency ◽

Test Sample ◽

Opening Angle ◽

Maximum Pressure ◽

Intake Valve ◽

Engine Simulation ◽

Exhaust Temperature ◽

Virtual Test

The diesel engine simulation model build by the GT-POWER software was tested and verified. The advance angle of injection, the opening angle of intake valve and the opening angle of exhaust valve was calculated to get the virtual test sample of diesel engine running under the rated condition. The optimization model was built based on the genetic algorithm, and three parameters were optimized aimed at the economic efficiency under the constraint of the maximum pressure in cylinder and the exhaust temperature; the error between the optimization and the simulation result was below 3%.

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