Evaluating the scavenging process by the scavenging curve of an opposed-piston, two-stroke (OP2S) diesel engine

Yang, Wei; Li, Xiangrong; Kang, Yuning; Zuo, Hao; Liu, Fushui

doi:10.1016/j.applthermaleng.2018.10.095

Cited by 18 publications

(9 citation statements)

References 14 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In terms of crankshaft phasing, the 0-20 • range in Table 5 is an extension of the 8-12 • exhaust crank angle lead range investigated by Achates Power on their opposed-piston GCI engine [42] (p. 3, Table 1), while the earlier Achates Power OP2S diesel engine employed a fixed 13.5 • crankshaft phase angle [43]. Regarding port heights, Yang et al suggest the optimal port height-to-stroke ratio should lay in the range 0.11-0.15 for most engines [34] (p. 345, Figure 23), while ranges of approx. 0.08-0.12 and 0.12-0.17 were investigated, respectively, for intake and exhaust port height-to-stroke ratios in the work by Ma et al [33] (p. 9, Table 3).…”

Section: Design Of Experimentsmentioning

confidence: 99%

“…In further uniflow scavenging simulations [33] they conclude that the intake port heightto-stroke ratio is the most important factor affecting delivery ratio, and the exhaust port height-to-stroke ratio affects engine delivery ratio and scavenging efficiency. Yang et al [34] also studied the effect of port height on the scavenging process in an OP2S diesel engine, using a 3D model validated against experiments. They emphasize the value of the scavenging curve in providing insight into the optimization of port height.…”

Section: Scavenging In Op2s Enginesmentioning

confidence: 99%

“…0.08-0.12 and 0.12-0.17 were investigated, respectively, for intake and exhaust port height-to-stroke ratios in the work by Ma et al [33] (p. 9, Table 3). Note that exhaust port heights are generally larger than those of the intake since increasing the former has the greater effect in improving the scavenging process [34], hence the different ranges stated.…”

Section: Design Of Experimentsmentioning

confidence: 99%

See 2 more Smart Citations

The Effect of Crankshaft Phasing and Port Timing Asymmetry on Opposed-Piston Engine Thermal Efficiency

et al. 2021

View full text Add to dashboard Cite

Opposed-piston, two-stroke engines reveal degrees of freedom that make them excellent candidates for next generation, highly efficient internal combustion engines for hybrid electric vehicles and power systems. This article reports simulation results that explore the influence of key control and geometrical parameters, specifically crankshaft phasing and intake and exhaust port height-to-stroke ratios, in obtaining best thermal efficiency. A model of a 0.75 L, single-cylinder opposed-piston two-stroke engine is exercised to predict fuel consumption as engine speed, load, crankshaft phasing, intake and exhaust port height-to-stroke ratios, and stoichiometry are varied for medium-duty truck and range extender applications. Under stoichiometric operation, optimal crankshaft phasing is seen at 0–5°, lower than reported in the literature. If stoichiometric operation is not mandated, best fuel consumption is achieved at an air-to-fuel equivalence ratio λ = 1.25 and 5–10° crankshaft phase angle, enabling a ~10 g/kWh (~4%) improvement in average brake-specific fuel consumption across medium-duty truck operating points. In range extender form, the engine provides 30 kW output power in accordance with a survey of range extender engines. In this role, there is a clear distinction between low-speed, high-load operation and vice versa. The decision as to which is more appropriate would be based on minimizing total owning and operating cost, itself a trade-off between better thermal efficiency (and thus lower fuel cost) and greater durability.

show abstract

Section: Design Of Experimentsmentioning

confidence: 99%

Section: Scavenging In Op2s Enginesmentioning

confidence: 99%

Section: Design Of Experimentsmentioning

confidence: 99%

See 1 more Smart Citation

The Effect of Crankshaft Phasing and Port Timing Asymmetry on Opposed-Piston Engine Thermal Efficiency

et al. 2021

View full text Add to dashboard Cite

show abstract

“…The Achates Power [3], by optimizing the piston trajectory and intake ports, achieved the thermal efficiency of 46% in an OP2S diesel engine, which is a total breakthrough. Fukang Ma, Changlu Zhao, et al, designed tracer gas test methods to optimize the scavenging efficiency [4]. Later on, they reached 170kw for their OP2S engine.…”

Section: Introductionmentioning

confidence: 99%

Design of opposed piston 2-stroke internal combustion engine test platform

Pei

Qiu

Chen

et al. 2022

J. Phys.: Conf. Ser.

View full text Add to dashboard Cite

Opposed piston two-stroke engine, due to its characteristics of fast expansion, high power density and indicate efficiency, and dynamic balancing, attracts many researchers’ attention. In order to explore its combustion performance, a novel test platform consisting of a drive system and combustion control system is proposed in this paper. The drive system mainly contains a 75-kW induction motor, a synchronous gearbox, and two crankshaft mechanisms. The displacement of the piston and chamber pressure is acquired and used to control combustion parameters. Using this mechanical device, the rotary motion can be converted to the opposite movement of the two pistons precisely. All the designed functions of the platform are verified by the combustion experiments of an opposed-piston two-stroke prototype. Furthermore, the experimental data is used to verify a one-dimension simulation model to evaluate the combustion characteristics of the prototype.

show abstract

“…As the engine speed increases, the intensity of turbulence in the cylinder increases, and subsequently the effect on the spray gradually increases. Yang et al investigated the air exchange process of OP2S diesel engines by building a three-dimensional model of the diesel engine and analyzing the effect of intake and exhaust port height on the intake process [17]. The effect of increasing the height of the intake and exhaust ports on the intake process was analyzed.…”

Section: Introductionmentioning

confidence: 99%

Experimental Investigation of Combustion Characteristics on Opposed Piston Two-Stroke Gasoline Direct Injection Engine

Yang

et al. 2021

Energies

Self Cite

View full text Add to dashboard Cite

The combustion characteristics of an opposed-piston two-stroke gasoline engine are investigated with experiment. The energy conversion and exergy destruction are analyzed and the organization method of the combustion process is summarized. The effects of phase difference, scavenging pressure, injection timing, ignition timing, and dual spark plug ignition scheme on the combustion process and engine performance are discussed, respectively. The heat release rate of the opposed-piston two-stroke gasoline engine is consistent with the conventional gasoline engine. With the increase of opposed-piston motion phase difference, the scavenging efficiency decreases and overmuch residual exhaust gas is not beneficial to the combustion process. Meanwhile, the faster relative velocity of the opposed-piston near the inner dead center enhances the cylinder working volume change rate, which leads to the rapid decline of in-cylinder pressure and temperature. The 15 °CA of opposed-piston motion phase difference improves the scavenging and combustion process effectively. When scavenging pressure is 0.12 MPa, the scavenging efficiency and heat release rate are improved at medium-high speed conditions. With the delay of injection timing, the flame developing period decreases gradually, and the rapid burning period decreases and then increases. The rapid burning period may reach the minimum value when the injection advance angle is 100 °CA. With the delay of ignition timing, the flame developing period increases gradually, and the rapid combustion period decreases and then increases. The rapid combustion period may reach the minimum value when the ignition advance angle is 20 °CA. Notably, the flat-top piston structure should be matched with the dual spark plug, which the ignition advance angle is 20 °CA at medium-high load conditions.

show abstract

Evaluating the scavenging process by the scavenging curve of an opposed-piston, two-stroke (OP2S) diesel engine

Cited by 18 publications

References 14 publications

The Effect of Crankshaft Phasing and Port Timing Asymmetry on Opposed-Piston Engine Thermal Efficiency

The Effect of Crankshaft Phasing and Port Timing Asymmetry on Opposed-Piston Engine Thermal Efficiency

Design of opposed piston 2-stroke internal combustion engine test platform

Experimental Investigation of Combustion Characteristics on Opposed Piston Two-Stroke Gasoline Direct Injection Engine

Contact Info

Product

Resources

About