Modeling of diesel spray tip penetration during start-of-injection transients

2020 ◽  
pp. 146808742095785
Author(s):  
Xinyi Zhou ◽  
Tie Li ◽  
Ping Yi
Keyword(s):  
Diesel Engines ◽  
Transient Processes ◽  
Long Distance ◽  
Spray Tip Penetration ◽  
Start Of Injection ◽  
Initial Stage ◽  
Multiple Injection Strategy ◽  
Opening And Closing ◽  
D Model ◽  
Injection Pulse

Multiple-injection strategy that has been applied widely in diesel engines usually features a short duration for each injection pulse. As a result, the shortened injection makes the needle opening and closing transients increasingly important for spray in an injection event. Owing to the needle movement, the spray development during the transient processes is complex and quite different from the spray at the quasi-steady state. However, so far modeling of the spray development during the transient processes is far from adequate. Particularly, a theoretical zero-dimensional (0-D) spray tip penetration model considering the needle opening and sac pressurization processes as well as ambient and injection conditions during the start-of-injection (SOI) transients is still absent. In this paper, considering the sac pressurization processes, the 0-D model of spray tip penetration during the SOI transients is derived. Then, the model is validated against the experimental spray data using a long-distance microscope together with an ultrahigh speed CMOS camera. The model and experimental results show that the spray tip penetration shows a t3/2 dependence at the initial stage of injection rather than the t dependence suggested by Hiroyasu’s model. Later, the spray tip penetration shows a t3/4 dependence owing to the spray breakup, and a t1/2 dependence with the completion of sac pressurization. The models and analysis are believed to provide new insights into the transient spray behaviors and valuable reference for engineers and researchers who are considering the model-based development of next-generation diesel engines.

scholarly journals Design and Build Temperature Control and Monitoring in Diesel Engines Using Mobile

2020 ◽  
Vol 10 (1) ◽  
pp. 31-37
Author(s):  
Mohammad Hasan Fuadi
Keyword(s):  
Diesel Engine ◽  
Temperature Control ◽  
Diesel Engines ◽  
Temperature Sensor ◽  
Cooling System ◽  
Cooling Water ◽  
Solenoid Valve ◽  
Valve Opening ◽  
Opening And Closing ◽  
And Control

Diesel engines is generally used for industrial and agricultural machines. Few people care about the engine temperature so it is forced to reach temperature of 100oC, which causes overheating of the diesel engine and has an impact on the performance itself. This also uses a hopper cooling system which is certainly not effective, because it's necessary to see that the water in the reservoir is still or not, also not equipped with an engine temperature display so it's difficult to ascertain the temperature inside. This study aims to monitor and control the temperature of cooling water. Operation of temperature control uses a telecontrol system that is connected to network (Internet of Things) so diesel temperature control can be done remotely. Monitoring of temperature and water level in the reserve tank using Web Mobile. In addition, there is a temperature sensor that is used to measure the temperature of the cooling water so that users can monitor the temperature of the diesel engine on Web Mobile. The test results obtained, the temperature sensor has an average temperature reading error of 0.031004%. Diesel engines with controlled solenoid valve cooling systems can produce ideal temperatures compared to when the solenoid valve is open (using the radiator continuously) or when the solenoid valve is Closed (without using a radiator). When the solenoid is controlled the engine temperature can be ideal because the solenoid valve opening and closing system has the lowest temperature of 56.34oC and the highest temperature of only 80.85oC.

Quasi-Dimensional Diesel Engine Combustion Modeling With Improved Diesel Spray Tip Penetration, Ignition Delay, and Heat Release Submodels

2017 ◽  
Vol 139 (11) ◽  
Author(s):  
Shuonan Xu ◽  
Hirotaka Yamakawa ◽  
Keiya Nishida ◽  
Zoran Filipi
Keyword(s):  
Diesel Engine ◽  
Heat Release ◽  
Diesel Engines ◽  
Ignition Delay ◽  
Air Entrainment ◽  
Oxygen Mixture ◽  
Diesel Spray ◽  
Spray Tip Penetration ◽  
Simulation Tools ◽  
The Impact

Increasingly stringent fuel economy and CO2 emission regulations provide a strong impetus for development of high-efficiency engine technologies. Diesel engines dominate the heavy duty market and significant segments of the global light duty market due to their intrinsically higher thermal efficiency compared to spark-ignited (SI) engine counterparts. Predictive simulation tools can significantly reduce the time and cost associated with optimization of engine injection strategies, and enable investigation over a broad operating space unconstrained by availability of prototype hardware. In comparison with 0D/1D and 3D simulations, Quasi-Dimensional (quasi-D) models offer a balance between predictiveness and computational effort, thus making them very suitable for enhancing the fidelity of engine system simulation tools. A most widely used approach for diesel engine applications is a multizone spray and combustion model pioneered by Hiroyasu and his group. It divides diesel spray into packets and tracks fuel evaporation, air entrainment, gas properties, and ignition delay (induction time) individually during the injection and combustion event. However, original submodels are not well suited for modern diesel engines, and the main objective of this work is to develop a multizonal simulation capable of capturing the impact of high-injection pressures and exhaust gas recirculation (EGR). In particular, a new spray tip penetration submodel is developed based on measurements obtained in a high-pressure, high-temperature constant volume combustion vessel for pressures as high as 1450 bar. Next, ignition delay correlation is modified to capture the effect of reduced oxygen concentration in engines with EGR, and an algorithm considering the chemical reaction rate of hydrocarbon–oxygen mixture improves prediction of the heat release rates. Spray and combustion predictions were validated with experiments on a single-cylinder diesel engine with common rail fuel injection, charge boosting, and EGR.

The two prime movers of globalization: history and impact of diesel engines and gas turbines

2007 ◽  
Vol 2 (3) ◽  
pp. 373-394 ◽  
Author(s):  
Vaclav Smil
Keyword(s):  
Multinational Corporations ◽  
Diesel Engines ◽  
Gas Turbines ◽  
Raw Materials ◽  
Mass Scale ◽  
Long Distance ◽  
Long Distance Transport ◽  
Ocean Shipping ◽  
History Of ◽  
Prime Movers

AbstractModern economic globalization would be impossible without our ability to move billions of tonnes of raw materials and finished goods among the continents and to fly at speeds approaching the speed of sound. These realities were made possible by the interaction of economic and technical factors. Much has been written about their organizational and political underpinnings (ranging from the role of multinational corporations to the history of free trade agreements), but much less on the history of the two prime movers that made these realities possible. Neither steam engines, nor gasoline-fuelled engines could have accomplished comparable feats. Diesel engines made ocean shipping the cheapest mode of long-distance transport and without gas turbines there would be no fast, inexpensive, mass-scale intercontinental travel. This paper examines the history, advances, benefits and costs of the two prime movers.

scholarly journals Spray Characteristics at Preheating Temperatur of Diesel-Biodiesel-Gasoline Fuel Blend

2021 ◽  
Vol 5 (2) ◽  
pp. 134
Author(s):  
Moch Miftahul Arifin ◽  
Nasrul Ilminnafik ◽  
Muh. Nurkoyim Kustanto ◽  
Agus Triono
Keyword(s):  
Diesel Engines ◽  
High Speed ◽  
Fuel Injection ◽  
Fuel Mixture ◽  
Spray Angle ◽  
Injection System ◽  
Spray Characteristics ◽  
Fuel Blend ◽  
Spray Tip Penetration

Technological developments in diesel engines require improvements to the fuel injection system to meet the criteria for economical, high-power and efficient combustion and meet environmental regulatory standards. One method that has a lot of interest is changing the characteristics of the fuel, with the aim of producing optimal combustion. Spray characteristics have a big role in determining the quality of combustion in diesel engines. A good spray can improve the quality of fuel atomization and the homogeneity of the air-fuel mixture in the combustion chamber so that it can produce good engine performance and low emissions. This study aims to determine the effect of a diesel-biodiesel (Calophyllum inophyllum)-gasoline blendandfuel heating on the spray characteristics. The research was conducted with variations in composition (B0, B100, B30, B30G5 and B30G10) and fuel heating (40, 60, 80, and 100 °C). Fuel injected atapressure of 17 MPa in to a pressure chamber of 3 bar. The spray formed was recorded with a high-speed camera of 480 fps (resolution 224x168 pixel). In B100 biodiesel, the highest viscosity and density cause high spray tip penetration, small spray angle, and high spray velocity. The addition of diesel oil, gasoline, and heating fuel reduces the viscosity and density so that the spray tip penetration decreases, the spray angle increases and the velocity of spray decreases.

scholarly journals Comparison of structural and operational parameters of selected Euro 6 engines used in long distance commercial vehicles

2015 ◽  
Vol 163 (4) ◽  
pp. 3-14
Author(s):  
Dariusz PIERNIKARSKI
Keyword(s):  
Comparative Analysis ◽  
Diesel Engines ◽  
Heavy Duty ◽  
Operational Parameters ◽  
Commercial Vehicles ◽  
Long Distance ◽  
Heavy Duty Diesel ◽  
Technical Solutions

The article presents the most important technical solutions used in heavy duty diesel engines powering commercial vehicles – namely tractors – that meet the requirements of the Euro 6 norm. A comparative analysis of selected structural and operational parameters was also made on the example of engines with typical displacement close to 13 dm3 used in long-distance tractors.

scholarly journals An Improved Sign Language Translation Model with Explainable Adaptations for Processing Long Sign Sentences

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Jiangbin Zheng ◽  
Zheng Zhao ◽  
Min Chen ◽  
Jing Chen ◽  
Chong Wu ◽  
...  
Keyword(s):  
Sign Language ◽  
State Of The Art ◽  
Language Translation ◽  
Resource Consumption ◽  
Long Distance ◽  
Neural Machine Translation ◽  
Initial Stage ◽  
Proposed Model ◽  
Stream Density ◽  
Current Systems

Sign language translation (SLT) is an important application to bridge the communication gap between deaf and hearing people. In recent years, the research on the SLT based on neural translation frameworks has attracted wide attention. Despite the progress, current SLT research is still in the initial stage. In fact, current systems perform poorly in processing long sign sentences, which often involve long-distance dependencies and require large resource consumption. To tackle this problem, we propose two explainable adaptations to the traditional neural SLT models using optimized tokenization-related modules. First, we introduce a frame stream density compression (FSDC) algorithm for detecting and reducing the redundant similar frames, which effectively shortens the long sign sentences without losing information. Then, we replace the traditional encoder in a neural machine translation (NMT) module with an improved architecture, which incorporates a temporal convolution (T-Conv) unit and a dynamic hierarchical bidirectional GRU (DH-BiGRU) unit sequentially. The improved component takes the temporal tokenization information into consideration to extract deeper information with reasonable resource consumption. Our experiments on the RWTH-PHOENIX-Weather 2014T dataset show that the proposed model outperforms the state-of-the-art baseline up to about 1.5+ BLEU-4 score gains.

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