scholarly journals Simulation study on effect of late-intake-valve-closing Atkinson cycle on the performance of a direct injection engine based on fuel economy

2021 ◽  
Vol 260 ◽  
pp. 01017
Author(s):  
Yue Li ◽  
Zhi Ning ◽  
Ming Lü ◽  
Xin Zhi ◽  
Xian Luo
Keyword(s):  
Fuel Economy ◽  
Direct Injection ◽  
Simulation Software ◽  
Engine Fuel ◽  
Intake Valve ◽  
Direct Injection Engine ◽  
Atkinson Cycle ◽  
Partial Load ◽  
Hybrid Engines ◽  
The Impact

Given the wide application of hybrid engines, how to improve hybrid engine fuel economy is being more and more studied, and using the Atkinson cycle to improve fuel economy is considered effective. In this study, the in-cylinder direct injection engine model was established with the data obtained from a benchmarking test using the GT-POWER simulation software. The working process of this engine was simulated after using Atkinson cycle. This simulation primarily focused on the research of the impact on engine fuel economy with different late intake valve closing strategies. The simulation results were calculated under the partial load conditions which are typically used in hybrid engines. The results indicated that engine fuel economy improved and fuel consumption decreased by using the Atkinson cycle. However, the Atkinson cycle would cause a decrease in power.

scholarly journals Experimental study on the effects of the Miller cycle on the performance and emissions of a downsized turbocharged gasoline direct injection engine

2020 ◽  
Vol 12 (5) ◽  
pp. 168781402091872
Author(s):  
Zhao-Ming Huang ◽  
Kai Shen ◽  
Li Wang ◽  
Wei-Guo Chen ◽  
Jin-Yuan Pan
Keyword(s):  
Compression Ratio ◽  
Fuel Economy ◽  
Direct Injection ◽  
Gasoline Direct Injection ◽  
Miller Cycle ◽  
Power Performance ◽  
Direct Injection Engine ◽  
Performance And Emission ◽  
Gasoline Direct Injection Engine ◽  
Partial Load

The Miller cycle has been proven to be an effective way to improve the thermal efficiency for gasoline engines. However, it may show insufficient power performance at certain loads. In this study, the objective is to exploit the advantages of the Miller-cycle engines over the original Otto-cycle engines. Therefore, a new camshaft profile with early intake valve closure was devised, and two various pistons were redesigned to obtain higher compression ratio 11.2 and 12.1, based on the original engine with compression ratio 10. Then, a detailed comparative investigation of the effects of Miller cycle combined with higher compression ratio on the performance and emission of a turbocharged gasoline direct injection engine has been experimentally carried out based on the engine bench at full and partial loads, compared to the original engine. The results show that, at full load, for a turbocharged gasoline direct injection engine utilizing the Miller cycle, partial maximum power is compromised about 1.5% while fuel consumption shows a strong correlation with engine speed. At partial load, since the Miller effect can well reduce the pumping mean effective pressure, thus improves the fuel economy effectively. In addition, the suppression of the in-cylinder combustion temperature induced by the lower effective compression ratio contributes to the reduction of nitrogen oxide emission greatly. However, the total hydrocarbon emission increases slightly. Therefore, a combination of the Miller cycle and highly boosted turbocharger shows great potential in further improvement of fuel economy and anti-knock performance for downsized gasoline direct injection engines.

The effects of cylinder deactivation on the thermal behaviour and fuel economy of a three-cylinder direct injection spark ignition gasoline engine

2018 ◽  
Vol 233 (11) ◽  
pp. 2838-2849
Author(s):  
Michael McGhee ◽  
Ziman Wang ◽  
Alexander Bech ◽  
Paul J Shayler ◽  
Dennis Witt
Keyword(s):  
Fuel Economy ◽  
Gasoline Engine ◽  
Thermal State ◽  
Direct Injection ◽  
Spark Ignition ◽  
Combustion Efficiency ◽  
Spark Ignition Engine ◽  
Engine Fuel ◽  
Cylinder Deactivation ◽  
Direct Injection Spark Ignition

The changes in thermal state, emissions and fuel economy of a 1.0-L, three-cylinder direct injection spark ignition engine when a cylinder is deactivated have been explored experimentally. Cylinder deactivation improved engine fuel economy by up to 15% at light engine loads by reducing pumping work, raising indicated thermal efficiency and raising combustion efficiency. Penalties included an increase in NOx emissions and small increases in rubbing friction and gas work losses of the deactivated cylinder. The cyclic pressure variation in the deactivated cylinder falls rapidly after deactivation through blow-by and heat transfer losses. After around seven cycles, the motoring loss is ~2 J/cycle. Engine structural temperatures settle within an 8- to 13-s interval after a switch between two- and three-cylinder operation. Engine heat rejection to coolant is reduced by ~13% by deactivating a cylinder, extending coolant warm-up time to thermostat-opening by 102 s.

scholarly journals Impingement characteristics of an early injection gasoline direct injection engine: A numerical study

2016 ◽  
Vol 18 (4) ◽  
pp. 378-393 ◽  
Author(s):  
Nicholas J Beavis ◽  
Salah S Ibrahim ◽  
Weeratunge Malalasekera
Keyword(s):  
Liquid Film ◽  
Film Formation ◽  
Direct Injection ◽  
Cylinder Liner ◽  
Gasoline Direct Injection ◽  
Intake Valve ◽  
Direct Injection Engine ◽  
Gasoline Direct Injection Engine ◽  
Start Of Injection ◽  
Early Injection

This article describes the use of a Lagrangian discrete droplet model to evaluate the liquid fuel impingement characteristics on the internal surfaces of an early injection gasoline direct injection engine. This study focuses on fuel impingement on the intake valve and cylinder liner between start of injection and 20° after start of injection using both a single- and a multi-component fuels. The single-component fuel used was iso-octane and the multi-component fuel contained fractions of iso-pentane, iso-octane and n-decane to represent the light, medium and heavy fuel fractions of gasoline, respectively. A detailed description of the impingement and liquid film modelling approach is also provided. Fuel properties, wall surface temperature and droplet Weber number and Laplace number were used to quantify the impingement regime for different fuel fractions and correlated well with the predicted onset of liquid film formation. Evidence of film stripping was seen from the liquid film formed on the side of the intake valve head with subsequent ejected droplets being a likely source of unburned hydrocarbons and particulate matter emissions. Differences in impingement location and subsequent location of liquid film formation were also observed between single- and multi-component fuels. A qualitative comparison with experimental cylinder liner impingement data showed the model to well predict the timing and positioning of the liner fuel impingement.

Development Concept for Non Conventional Hybrid Engine

2010 ◽  
Author(s):  
Harsh Purohit ◽  
Ankit Shah ◽  
Nishant Parekh ◽  
Akash Pandey
Keyword(s):  
Fuel Economy ◽  
Internal Combustion Engines ◽  
Gasoline Engine ◽  
Direct Injection ◽  
Combustion Engines ◽  
Common People ◽  
Advantages And Disadvantages ◽  
Compact Size ◽  
Hybrid Engines ◽  
Variable Valve

Environmental issues and the need for environment-friendly transport have always been a priority for the world due to ever increasing demand of modes of transport. So developing quick and eco friendly vehicle is the trend as of now with most manufacturers globally. There are numerous ways in which manufacturers have tackled these issues. Some of the common approaches undertaken are refinements of existing internal combustion engines. Like developing technologies such as direct injection, VVT (variable valve time), VTEC (variable valve time electronic lift), VGT (variable geometry turbines), reducing engine friction and weight, cam less engines, micro hybrids, etc But the best/optimum compromise between eco friendliness and urge to develop more power with good fuel economy and reduced emission is best met by the development of hybrid engines. Thermal and electric engines both have advantages and disadvantages that are often complementary. Combustion engines offer better range, power and ‘lunge’, but give out exhaust gas, although the current Euro IV norm place strict limits on these. Electric engines are zero-emission and offer very quick pick-up from a stopped position, but the batteries have low range and limited speed. So this complementation of both power trains is exploited in hybrid engines. Now conventional hybrids have many disadvantages such as being bulky with additional weight of battery packs and motors and other auxiliary transmission components, complex and dangerous electric systems, etc. So it is proposed to develop a non conventional hybrid engine which produces power at par with the conventional one and releases emission which is compatible with the stringent emission norms set for the conventional hybrids with considerably lucrative fuel economy comparable with the currently available hybrids in market and yet overcome the drawbacks of the conventional hybrid engines. Also the compact size of the hybrid engine that we propose makes it quite viable to fitted in small vehicles (like bikes, compact cars, etc) which further makes it a more promising technology that can be made available to common people across the globe and there by lead to a better transportation system for people of all class and need. The conceptualization basically includes modification of an inline twin cylinder or a v-twin 4-stroke gasoline engine as a preliminary step towards achieving the above proposed objectives.

Sign in / Sign up

Export Citation Format

Share Document