CFD Modeling of In-Cylinder Fuel-Air Mixing in a CNG-Fuelled SI Engine with Port Gas Injection

2010 ◽  
Author(s):  
Manish Garg ◽  
R Ravikrishna
Keyword(s):  
Gas Injection ◽  
Cfd Modeling ◽  
Si Engine ◽  
Air Mixing

scholarly journals Indoor Airflow Distribution in Repository Design: Experimental and Numerical Microclimate Analysis of an Archive

Buildings ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 152
Author(s):  
Karin Kompatscher ◽  
Rick P. Kramer ◽  
Bart Ankersmit ◽  
Henk L. Schellen
Keyword(s):  
Vertical Gradient ◽  
Building Envelope ◽  
Cfd Modeling ◽  
Indoor Climate ◽  
Ambient Conditions ◽  
Climate Control ◽  
Climate Conditions ◽  
Airflow Distribution ◽  
Air Mixing ◽  
Delay Variations

The majority of cultural heritage is stored in archives, libraries and museum storage spaces. To reduce degradation risks, many archives adopt the use of archival boxes, among other means, to provide the necessary climate control and comply with strict legislation requirements regarding temperature and relative air humidity. A strict ambient indoor climate is assumed to provide adequate environmental conditions near objects. Guidelines and legislation provide requirements for ambient indoor climate parameters, but often do not consider other factors that influence the near-object environment, such as the use of archival boxes, airflow distribution and archival rack placement. This study aimed to provide more insight into the relation between the ambient indoor conditions in repositories and the hygrothermal conditions surrounding the collection. Comprehensive measurements were performed in a case study archive to collect ambient, local and near-object conditions. Both measurements and computational fluid dynamics (CFD) modeling were used to research temperature/relative humidity gradients and airflow distribution with a changing rack orientation, climate control strategy and supply as well as exhaust set-up in a repository. The following conclusions are presented: (i) supplying air from one air handling unit to multiple repositories on different floors leads to small temperature differences between them. Differences in ambient and local climates are noticed; (ii) archival boxes mute and delay variations in ambient conditions as expected—however, thermal radiation from the building envelope may have a large influence on the climate conditions in a box; (iii) adopting night reduction for energy conservation results in an increased influence of the external climate, with adequate insulation, this effect should be mitigated; and (iv) the specific locations of the supply air and extraction of air resulted in a vertical gradient of temperature and insufficient mixing of air, and adequate ventilation strategies should enhance sufficient air mixing in combination with the insulation of external walls, and gradient forming should be reduced.

scholarly journals CFD Modeling and Experimental Validation of Top-Submerged-Lance Gas Injection in Liquid Metal

2020 ◽  
Vol 51 (4) ◽  
pp. 1509-1525
Author(s):  
D. Obiso ◽  
M. Akashi ◽  
S. Kriebitzsch ◽  
B. Meyer ◽  
M. Reuter ◽  
...  
Keyword(s):  
Liquid Metal ◽  
Experimental Validation ◽  
Gas Injection ◽  
Cfd Modeling ◽  
Submerged Lance

CFD Modeling of Gas Exchange, Fuel-Air Mixing and Combustion in Gasoline Direct-Injection Engines

2019 ◽  
Author(s):  
Tommaso Lucchini ◽  
Gianluca D'Errico ◽  
Davide Paredi ◽  
Lorenzo Sforza ◽  
Angelo Onorati
Keyword(s):  
Gas Exchange ◽  
Direct Injection ◽  
Gasoline Direct Injection ◽  
Cfd Modeling ◽  
Direct Injection Engines ◽  
Air Mixing

Multi-Dimensional Modeling of Direct Natural-Gas Injection and Mixture Formation in a Stratified-Charge SI Engine with Centrally Mounted Injector

2008 ◽  
Vol 1 (1) ◽  
pp. 607-626 ◽  
Author(s):  
Mirko Baratta ◽  
Andrea E. Catania ◽  
Ezio Spessa ◽  
Lothar Herrmann ◽  
Klaus Roessler
Keyword(s):  
Natural Gas ◽  
Gas Injection ◽  
Si Engine ◽  
Mixture Formation ◽  
Stratified Charge ◽  
Dimensional Modeling

3D CFD modeling of natural draft wet-cooling tower with flue gas injection

2015 ◽  
Vol 91 ◽  
pp. 824-833 ◽  
Author(s):  
Adam Klimanek ◽  
Michał Cedzich ◽  
Ryszard Białecki
Keyword(s):  
Flue Gas ◽  
Cooling Tower ◽  
Gas Injection ◽  
Cfd Modeling ◽  
Natural Draft

Effect of Injection Timing on Fuel-Air Mixing and Combustion in a Direct Injection Stratified Charge SI Engine

2007 ◽  
Author(s):  
T. Anand Kumar ◽  
J. M. Mallikarjuna ◽  
V. Ganesan
Keyword(s):  
Numerical Study ◽  
Direct Injection ◽  
Combustion Characteristics ◽  
Spark Ignition Engine ◽  
Injection Timing ◽  
Flame Surface ◽  
Si Engine ◽  
Stratified Charge ◽  
Spark Plug ◽  
Air Mixing

This paper describes a numerical study on fuel-air mixing and combustion in a direct injection stratified charge spark ignition engine. The in-cylinder flow, fuel-air mixing and combustion characteristics are investigated in a single cylinder, four-valve, four stoke, direct injection SI engine with pent-roof head and reverse tumble ports. The engine combustion chamber had the side mounted injector and spark plug at the center of pent-roof. Wall guided fuel-air mixing scheme has been adopted. The pre processor code Es-ice, used for dynamic grid generation preparation including description of piston and valve motion. Commercial computational fluid dynamics code Star-CD is used for solving governing equations and post processing of results. Combustion in the present study is simulated using Extended Coherent Flame Model-3z (ECFM-3Z). This model is based on a flame surface density transport equation that can describe inhomogeneous turbulent premixed combustion. In the present study, engine simulations has been carried out from 370 CAD before TDC and upto 90 CAD aTDC. The process includes the closing of the exhaust valves, the whole intake stroke, injection, combustion, and part of expansion. Three different injection timings are simulated viz. 55, 60 and 65 CAD bTDC. For validation of the code predicted results are compared with experimental results available in the literature. It is observed that, injection timing has an important role in mixture preparation and distribution around the spark plug. Hence, for the better combustion characteristics start of injection timing should be optimized.

scholarly journals CFD Modeling of Multiphase Flow in an SKS Furnace with New Tuyere Arrangements

2021 ◽  
Author(s):  
Kezhou Song ◽  
Ari Jokilaakso
Keyword(s):  
Shear Stress ◽  
Wall Shear Stress ◽  
Gas Flow ◽  
Model Simulation ◽  
Gas Injection ◽  
Side Wall ◽  
Copper Smelting ◽  
Cfd Modeling ◽  
Injection Speed ◽  
Wall Shear

AbstractThere has been a great deal of focus on the optimization of tuyere arrangements in SKS bottom blown copper smelting furnaces since the last decade, as the improved furnace operation efficiency of SKS technology has potential that cannot be ignored. New –x + 0 + x deg tuyere arrangements with 14 tuyeres are proposed in this research paper. Using a previously verified numerical model, CFD tests on the velocity distribution and wall shear stress for scaled-down SKS furnace models were conducted, with a constant total volumetric gas flow rate, and different operating parameters and furnace cross-section geometries. The results indicate that, at a relatively low gas injection speed compared with the previously optimized tuyere arrangement, although the –x +0 +x deg tuyere arrangements are unable to supply enhanced agitation in the typical round furnaces, they achieve better performance in elliptical furnaces. At a comparatively higher gas injection speed, the – x + 0 + x deg tuyere arrangements can improve the agitation performance in a round furnace while maintaining an acceptable wall shear stress on the bottom and side wall. The agitation enhancement with the − x +0 +x deg tuyere arrangements can essentially be attributed to stronger interactions between bubble plumes and furnace side walls. To further exploit the advantages of the new tuyere arrangements, an optimized tuyere angle was confirmed by a full-scale furnace model simulation.

Recovery boiler sootblowers: History and technological advances

TAPPI Journal ◽  
2015 ◽  
Vol 14 (1) ◽  
pp. 51-60
Author(s):  
HONGHI TRAN ◽  
DANNY TANDRA
Keyword(s):  
Cfd Modeling ◽  
Computing Systems ◽  
The Past ◽  
Technological Advances ◽  
Recovery Boilers ◽  
Computational Fluid Dynamics Cfd ◽  
Recovery Boiler ◽  
Steam Parameters ◽  
Insight Into ◽  
Deposit Removal

Sootblowing technology used in recovery boilers originated from that used in coal-fired boilers. It started with manual cleaning with hand lancing and hand blowing, and evolved slowly into online sootblowing using retractable sootblowers. Since 1991, intensive research and development has focused on sootblowing jet fundamentals and deposit removal in recovery boilers. The results have provided much insight into sootblower jet hydrodynamics, how a sootblower jet interacts with tubes and deposits, and factors influencing its deposit removal efficiency, and have led to two important innovations: fully-expanded sootblower nozzles that are used in virtually all recovery boilers today, and the low pressure sootblowing technology that has been implemented in several new recovery boilers. The availability of powerful computing systems, superfast microprocessors and data acquisition systems, and versatile computational fluid dynamics (CFD) modeling capability in the past two decades has also contributed greatly to the advancement of sootblowing technology. High quality infrared inspection cameras have enabled mills to inspect the deposit buildup conditions in the boiler during operation, and helped identify problems with sootblower lance swinging and superheater platens and boiler bank tube vibrations. As the recovery boiler firing capacity and steam parameters have increased markedly in recent years, sootblowers have become larger and longer, and this can present a challenge in terms of both sootblower design and operation.

Sign in / Sign up

Export Citation Format

Share Document