Stroke Cycle Engine Research Articles

Observational Analysis of Stationary C.I. Engine Output and Emission Evaluation for Variance of Induction Pressure Aspects

In the current environment, improved engine performance, reduced fuel consumption and reduced emissions are important goals for automotive manufacturers. To understand the factors involved in the compartment assemblies in Compression Ignition (C I) engines it is crucial to concentrate on such goals. Pressure rating, fuel atomization, fuel pressure, fuel quality, air pressure rating, air temperature, pressure and other design components such as piston, Air induction system, and assembly chamber and more to work. It is evident from the literature review and research work carried out to date that the airing system is best method of promoting C I operation of the engine. The design of the Air suction system could be achieved in this way that it takes into account the objectives of entire system. Effective air suction system improvement needs least energy utilization and most extreme use of air intake pressure for decrease in poisonous productions at outlet of C I engines. Furthermore, powerful use of fuel vitality. In present work, air suction arrangement, exclusively less air inlet pressure during suction stroke of four stroke cycle engine concern is topic of explicit enthusiasm for plan. Advancement of air induction system with air induction pressure regulator, flow distribution, action is studied and useful information is developed through proper intake manifold arrangement for better fuel efficiency.

A comparison between Miller and five-stroke cycles for enabling deeply downsized, highly boosted, spark-ignition engines with ultra expansion

It has been well known that the engine downsizing combined with intake boosting is an effective way to improve the fuel conversion efficiency without penalizing the engine torque performance. However, the potential of engine downsizing is not yet fully explored, and the major hurdles include the knocking combustion and the pre-turbine temperature limit, owing to the aggressive intake boosting. Using the engine cycle simulation, this paper compares the effects of the Miller and five stroke cycles on the performance of the deeply downsized and highly boosted SI engine, taking the engine knock and pre-turbine temperature into consideration. In the simulation, the downsizing is implemented by reducing the combustion cylinder number from four to two, while a two stage boosting system is designed for the deeply downsized engine to ensure the wide-open-throttle (WOT) performance comparable to the original four cylinder engine. The Miller cycle is realized by varying the intake valve timing and lift, while the five stroke cycle is enabled with addition of an extra expansion cylinder between the two combustion cylinders. After calibration and validation of the engine cycle simulation models using the experimental data in the original engine, the performances of the deeply downsized engines with both the Miller and five stroke cycles are numerically studied. For the most frequently operated points on the torque-speed map, at low loads the Miller cycle exhibits superior performance over the five-stroke cycle in terms of fuel conversion efficiency, while at higher loads the thermal efficiency of the five stroke cycle, owing primarily to elimination of fuel enrichment operations, is higher than that of the Miller cycle engine. For the WOT operation, even with the two-stage boosting system, at the engine speed below 1700rpm the deeply downsized engine with the Miller cycle fails to deliver the torque comparable to the original engine, while the targeted WOT torque can be achieved with the five stroke cycle engine at all the engine speeds but 800rpm. The mechanism of the efficiency differences between the Miller and five stroke cycles is discussed in depth with the energy balance and influencing factor analysis on thermal efficiency.

A study of a crankcase supercharged 4–stroke cycle engine through on–road tests using motorcycles and passenger cars

In order to investigate the transient characteristics of crankcase–supercharged 4–stroke cycle engines, such engines were tested on the road by installing one in both a motorcycle and a passenger car. It was found that, in the starting and the passing acceleration tests, the engine speed of the crankcase–supercharged engine increased more sharply than that of the naturally–aspirated engine. Additionally, in 0–200m starting acceleration tests, the crankcase–supercharged motorcycle's time was 4.7 sec faster than that of the naturally–aspirated motorcycles.

The Effect of Retrofit Technologies on Formaldehyde Emissions from a Large Bore Natural Gas Engine

Formaldehyde is an air toxic that is typically emitted from natural gas-fired internal combustion engines as a product of incomplete combustion. The United States Environmental Protection Agency (EPA) regulates air toxic emissions, including formaldehyde, from stationary reciprocating internal combustion engines. National air toxic standards are required under the 1990 Clean Air Act Amendments. This work investigates the effect that hardware modifications, or retrofit technologies, have on formaldehyde emissions from a large bore natural gas engine. The test engine is a Cooper-Bessemer GMV-4TF two stroke cycle engine with a 14” (35.6 cm) bore and a 14” (35.6 cm) stroke. The impact of modifications to the fuel injection and ignition systems are investigated. Data analysis and discussion is performed with reference to possible formaldehyde formation mechanisms and in-cylinder phenomena. The results show that high pressure fuel injection (HPFI) and precombustion chamber (PCC) ignition significantly reduce formaldehyde emissions

218 小型2ストローク機関におけるピストン表面近傍流れ計算手法の考察 : 圧縮・爆発・膨張の条件設定(熱力学3)

218 小型2ストローク機関におけるピストン表面近傍流れ計算手法の考察 : 圧縮・爆発・膨張の条件設定(熱力学3)

Performance of a 2 Stroke Cycle Spark Ignition Engine Fuelled with CNG Using Intermittent Fuel Injection from Scavenging Ports

Performance of a 2 stroke cycle engine fuelled with CNG (Compressed natural gas) using intermittent fuel injection from a scavenging port is investigated experimentally. The test engine is a 2 cylinder, 398 cm3, 2 stroke cycle spark ignition engine. Gaseous fuel injectors are attached at the cylinder block, and a CNG is injected into the scavenging passage through a fuel injection pipe. The fuel injection pressure is set at 0.255 MPa, and the fuel is injected intermittently during the scavenging process. The length and tip geometry of the fuel injection pipe are varied, and the effect on the engine performance is investigated. Using the scavenging port fuel injection, the BSFC is reduced by 25%, and the lean burn limit extends from λ= 1.2 to 1.46, at the maximum. The peak of the NOx emission shifts to leaner side, and the THC emission is reduced by 47 % at the maximum. It is_considered that the intermittent fuel injection from a scavenging port is effective to achieve stratified combustion and reduction in fuel short circuiting through the cylinder.

411 小型2ストローク機関におけるピストン表面近傍流れ計算手法の一考察 : 掃・排気孔締切後の圧縮・爆発・膨張の条件設定(熱工学 I,2.学術講演)

411 小型2ストローク機関におけるピストン表面近傍流れ計算手法の一考察 : 掃・排気孔締切後の圧縮・爆発・膨張の条件設定(熱工学 I,2.学術講演)

小型2ストローク機関におけるピストン表面近傍流れ計算手法における燃焼室デポジット影響評価方法の一考察(熱工学I-1)

小型2ストローク機関におけるピストン表面近傍流れ計算手法における燃焼室デポジット影響評価方法の一考察(熱工学I-1)

415 小型2ストローク機関におけるピストン表面近傍流れ計算手法の一考察 : 温度及びピストン稼動の条件設定(熱工学II)

415 小型2ストローク機関におけるピストン表面近傍流れ計算手法の一考察 : 温度及びピストン稼動の条件設定(熱工学II)

408 小型2ストローク機関におけるピストン表面近傍流れ計算手法の一考察 : エネルギ及び成分質量の各保存式の追加設定(応用熱工学(熱移動))

408 小型2ストローク機関におけるピストン表面近傍流れ計算手法の一考察 : エネルギ及び成分質量の各保存式の追加設定(応用熱工学(熱移動))

Air flow in cylinder of 2 cycle uniflow scavenging diesel engine at compression stroke. (1st report. Experimental results).

The scavenging process of a 2 stroke cycle engine dominates not only fresh air charging but also the air flow in a cylinder at the compression end. So, the combustion performance of a 2 stroke cycle diesel engine depends on the scavenging efficiency ηs and the scavenging air swirl intensity in the cylinder. In this report the scavenging air flow is investigated by motoring of a 2 cycle engine rig. From the LDV measurement of air velocity in a cylinder at the compression stroke, it is shown that the scavenging port made by the combination of a large angle port and a small angle port has high scavenging ability and sufficient swirl intensity for air-fuel mixing.

Limiting delivery ratio curves of crankcase-scavenged 2-stroke cycle engines (By throttling the inlet port)

In order to obtain the limiting delivery ratio curve, the relation-ships between delivery ratio and engine speed were investigated on the crankcase-scavenged 2 stroke-cycle engines by varing through wide limits the effective time area of the inlet ports. It was found that the mean inlet Mach number Mim already reported by the authors using the 4 stroke-cycle engines showed well the characteristics of limiting delivery ratio and when Mim approached a limit value the delivery ratio decreased hyperbolically with an increase in engine speed.

圧力波伝播モデルに基づく2サイクルエンジンの省エネルギー形排気管の設計

圧力波伝播モデルに基づく2サイクルエンジンの省エネルギー形排気管の設計

The Influence of Exhaust and Scavenging Time Area Design on the Engine Performance in the Poppet Valve Uniflow Two-Cycle Engine : Part 1, Fundamental Equations and Preliminary Calculations

In order to study the optimum design conditions of exhaust and scavenging time areas in a poppet valve uniflow two stroke cycle engine, a series of fundamental equations and methods of estimating the engine performance were derived by developing generalized dimensionless expressions. The possibility and accuracy of this calculation method could be checked by some calculations on a high speed three-cylinder diesel engine equipped with a mechanically driven blower.

The Trapping Efficiency Measurement of Two Stroke Cycle Diesel Engine by Tracer Gas Method

The authors of this paper studied on the tracer gas method which had already been suggested for application in measuring the trapping efficiency of two stroke cycle engines. And in consequence, the superiority in both accuracy and reproducibility of measurement under the following conditions was recognized : The use of anhydrous monomethylamine as the tracer gas ; gas concentration being 0.1 to 0.3% ; the use of 10 cc of 0.02 normal solution of sulfuric acid as the absorbing liquid ; a mixture of bromcresol-green and methyl-red as the neutralization reagent. The type of sampling tube, the gas sampling points and the gas sampling apparatus are also selected. The accuracy are compared with the results obtained by the gas sampling valve method. Under these conditions, the errors are within the range of ±2%.

The Trapping Efficiency Measurement of Two Stroke Cycle Diesel Engine by Tracer Gas Method

The authors studied the tracer gas method which had already been suggested to be an applicable method of measuring the trapping efficiency of two stroke cycle engines. And in consequence, the superioritv in both accuracy and possibility of reappearance under the following conditions of measurement was found : The use of anhydrous monomethylamine as the tracer gas ; gas density being 0.1∼0.3% ; the use of 10 cc of 0.02 normal solution of sulfuric acid as the absorbing liquid ; the type of sampling tube being as shown in Fig. 12 (a) ; a mixture of bromcresol-green and methyl-red as the neutralization reagent ; gas sampling points in Fig.5 (a) and Fig.5 (b) and the gas sampling apparatus in Fig.8. Under these conditions, the errors were within the range of ±2%. The accuracy was compared with the results obtained by the gas sampling valve method.