Simulation Study of Effects of Injection Rate Profile and Air Entrainment Characteristics on D.I. Diesel Combustion

1996 ◽  
Author(s):  
Hirofumi Imanishi ◽  
Takuo Yoshizaki ◽  
Hiroyuki Hiroyasu
Keyword(s):  
Simulation Study ◽  
Air Entrainment ◽  
Injection Rate ◽  
Diesel Combustion ◽  
Rate Profile

A new concept of actively controlled rate of diesel combustion (ACCORDIC): Part II—simultaneous improvements in brake thermal efficiency and heat loss with modified nozzles

2018 ◽  
Vol 20 (1) ◽  
pp. 34-45 ◽  
Author(s):  
Noboru Uchida ◽  
Hiroki Watanabe
Keyword(s):  
Heat Release ◽  
Heat Loss ◽  
Heat Release Rate ◽  
Release Rate ◽  
Thermal Efficiency ◽  
Air Entrainment ◽  
Diesel Combustion ◽  
Brake Thermal Efficiency ◽  
Rate Profile ◽  
Late Part

A new diffusion-based combustion concept (named it as Actively Controlled Rate of Diesel Combustion) for the confirmation of brake thermal efficiency optimum heat release rate profile based on multiple fuel injectors has been investigated. The outstanding results are; it is possible to achieve desired heat release rate profile only by the independent control of injection timing and duration of three injectors installed to a cylinder. The optimum brake thermal efficiency was not achieved with the Otto-like cycle but with the Sabathe-like cycle as predicted by a zero-dimensional thermodynamic model. Furthermore, smoke emissions were concurrently reduced with NOx emissions by increasing fuel amount from the side injectors without any deterioration in CO and total hydrocarbon emissions. On the other hand, brake thermal efficiency itself was not so improved than expected, because of lower heat release in the late part of combustion and unexpected less heat loss reduction. To solve these issues, combustion visualization and numerical simulation analysis were carried out. The results suggested that the adjacent sprays with narrower angle from each side injector deteriorated air entrainment and mixture formation, which might also result in the deterioration in wall heat loss in the expansion stroke. To solve both issues simultaneously, modified nozzle to inject against the swirl from the side injectors was utilized and achieved an improvement in both brake thermal efficiency and heat loss. That is the interdependent and reciprocal control of in-cylinder flow and fuel injection will be one of the breakthrough technologies for current trade-offs by the temporal and spatial spray flame optimization. Furthermore, the nozzle having higher flow rate with less number of orifice was utilized for the side injectors. Even though the smoke emissions were not optimized yet, brake thermal efficiency was much improved with higher heat release rate in the late part of combustion.

Helium-Injection Cooling of Hot Silica Glass Fiber in Optical Fiber Manufacturing System

2012 ◽  
Vol 157-158 ◽  
pp. 1301-1304
Author(s):  
Dong Joo Kim ◽  
Il Seok Oh ◽  
Ho Sang Kwak ◽  
Kyoung Jin Kim
Keyword(s):  
Optical Fiber ◽  
Glass Fiber ◽  
Glass Fibers ◽  
Air Entrainment ◽  
Injection Rate ◽  
Fiber Drawing ◽  
Cooling Effectiveness ◽  
Drawing Speed ◽  
Cooling Unit ◽  
Fiber Manufacturing

In an optical fiber manufacturing process, glass fibers drawn from the heated silica preform in the furnace should be sufficiently cooled down close to ambient temperature. As the fiber drawing speed continues to increase for better manufacturing productivity, the glass fiber cooling becomes more difficult and the use of helium injection into the glass fiber cooling unit is required to greatly enhance the fiber cooling effectiveness. The present study numerically simulates the flowfield and heat transfer phenomena on the glass fiber cooling in order to investigate the effects of helium injection and fiber drawing speed on the fiber cooling effectiveness of glass cooling unit. The results found that the amount of air entrainment at the unit inlet is the significant factor that decides the cooling effectiveness by significantly lowering the helium purity in cooling gas. Also, at a given fiber drawing speed, there exists a critical helium injection rate and the fiber cooling does not improve any more, even if the helium injection rate increases above this critical value.

scholarly journals Simulation Study of Hot Waterflood and WASP Injection Post Mature Steamflood

2020 ◽  
Vol 3 (2) ◽  
Author(s):  
Ludovika Jannoke ◽  
Iwan Setya Budi ◽  
Astra Agus Pramana
Keyword(s):  
Simulation Study ◽  
Reservoir Simulation ◽  
High Intensity ◽  
Steam Injection ◽  
Injection Rate ◽  
The World

<em>Steamflood is the most successful thermal EOR applied throughout the world and have produced the biggest portion of oil from EOR methods. As high intensity energy and associated cost are put to produce oil, optimization in any level can have tremendous impacts. Optimization in steamflood operation can be achieved by optimizing steam injection (rate, time), especially in mature pattern/ field or nearing the end of field life/ abandonment. This objective can be done thru utilization of retained heat in the reservoir and overburden/ underburden as they are not instantaneously produced with fluids. By using reservoir simulation, it can be shown that injection is not necessary to be continue until abandonment but can be stopped at a much earlier time hence a much profitable steamflood operation can be achieved.</em>

Control of the Diesel Combustion Process via Advanced Closed Loop Combustion Control and a Flexible Injection Rate Shaping Tool

2009 ◽  
Vol 2 (2) ◽  
pp. 362-375 ◽  
Author(s):  
Jan Hinkelbein ◽  
Can Sandikcioglu ◽  
Stefan Pischinger ◽  
Matthias Lamping ◽  
Thomas Körfer
Keyword(s):  
Closed Loop ◽  
Combustion Process ◽  
Injection Rate ◽  
Diesel Combustion ◽  
Combustion Control ◽  
Rate Shaping ◽  
Shaping Tool

Study of the influence of nozzle seat type on injection rate and spray behaviour

2005 ◽  
Vol 219 (5) ◽  
pp. 677-689 ◽  
Author(s):  
V Bermúdez ◽  
R Payri ◽  
F J Salvador ◽  
A H Plazas
Keyword(s):  
Steady Flow ◽  
Air Entrainment ◽  
Injection Rate ◽  
Point Of View ◽  
Flow Conditions ◽  
Test Rig ◽  
Spray Cone ◽  
Flow Test ◽  
Rate Test ◽  
Steady Flow Test

A deep analysis of the injection rate characteristics and spray behaviour of the most used nozzle types in diesel engines [microSAC and valve covered orifice (VCO)] has been carried out. In order to compare the injection characteristics and the spray behaviour of both nozzle types, several experimental installations were used, such as the steady flow test rig, injection rate test rig, spray momentum test rig, and nitrogen test rig, to obtain a full hydrodynamic and spray characterization. The study of the flow in both nozzles was analysed under steady flow conditions in the steady flow test rig and in real unsteady flow conditions in the injection rate test rig and the spray momentum test rig. The macroscopic properties of the spray (tip penetration and spray cone angle) were characterized using a high-pressure test rig. From the point of view of the internal flow behaviour, the results showed interesting differences in the permeability of both nozzle geometries, with a higher discharge coefficient in the microSAC nozzle. However, from the point of view of air entrainment, the results showed a better quality of fuel-air mixing in the VCO nozzle. Besides the evidence from the experimental results, a theoretical analysis was carried out in order to identify the most important parameters that determine the spray behaviour and thus justify the different macroscopic behaviour of both nozzles.

scholarly journals Experimental realisation of predefined diesel combustion processes using advanced closed-loop combustion control and injection rate shaping

2012 ◽  
Vol 13 (6) ◽  
pp. 607-615 ◽  
Author(s):  
Jan Hinkelbein ◽  
Florian Kremer ◽  
Matthias Lamping ◽  
Thomas Körfer ◽  
Joschka Schaub ◽  
...  
Keyword(s):  
Closed Loop ◽  
Injection Rate ◽  
Diesel Combustion ◽  
Combustion Control ◽  
Rate Shaping ◽  
Combustion Processes

scholarly journals EXPERIMENTAL STUDY ON THE INJECTION CHARACTERISTICS OF HYDROTREATED VEGETABLE OIL IN A DIESEL ENGINE COMMON RAIL SYSTEM

2022 ◽  
Vol 36 (06) ◽  
Author(s):  
VO TAN CHAU ◽  
DUONG HOANG LONG ◽  
CHINDA CHAROENPHONPHANICH
Keyword(s):  
Vegetable Oil ◽  
Fuel Injection ◽  
Injection Pressure ◽  
Injection Rate ◽  
Common Rail System ◽  
Nox Formation ◽  
Injection Process ◽  
Rate Profile ◽  
The Impact ◽  
Injection Pressures

The diesel combustion is primarily controlled by the fuel injection process. The start of injection therefore has a significant effect in the engine, which relates large amount of injected fuel at the beginning of injection to produces a strong burst of combustion with a high local temperature and high NOx formation. This paper investigated the impact of Hydrotreated Vegetable Oil (HVO) and blends of 10%, 20%, 30%, 50%, 80% by mass of HVO with commercial diesel fuel (mixed 7% FAME-B7) to injection process under the Zeuch’s method and compared to that of B7. The focus was on the injection flow rate in the variation of injection pressures, back pressures, and energizing times. The experimental results indicated that injection delay was inversely correlated to HVO fraction in the blend as well as injection pressure. At different injection pressures, HVO revealed a slightly lower injection rate than diesel that resulted in smaller injection quantity. Discharge coefficient was recognized larger with HVO and its blends. At 0.5ms of energizing time, injection rate profile displayed the incompletely opening of needle. Insignificant difference in injection rate was observed as increasing of back pressure.

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