Three-Dimensional Dynamic Characteristics of Transverse Fuel Injection into a Supersonic Crossflow

2008 ◽  
Author(s):  
Suhee Won ◽  
Edward Shin ◽  
D.-R. Cho ◽  
In-Seuck Jeung ◽  
J.-Y. Choi
Keyword(s):  
Dynamic Characteristics ◽  
Fuel Injection ◽  
Three Dimensional

The Influence of Needle Eccentric Motion On Hole-to-Hole Injection Characteristics of a Two-Layered 8-Hole Diesel Injector

2021 ◽  
Author(s):  
Tianyu Jin ◽  
Yu Sun ◽  
Chuqiao Wang ◽  
Adams Moro ◽  
Xiwen Wu ◽  
...  
Keyword(s):  
Fuel Injection ◽  
Lateral Displacement ◽  
Three Dimensional ◽  
Injection Rate ◽  
Hole Injection ◽  
Three Dimensional Model ◽  
Maximum Displacement ◽  
Fuel Flow ◽  
Diesel Injection ◽  
Eccentric Motion

Abstract The stringent emission regulations diesel engines are required to meet has resulted in the usage of multi-hole and ultra-multi-hole injectors, nowadays. In this research study, a double layered 8-hole diesel injection nozzle was investigated both numerically and experimentally. A three-dimensional model of the nozzle which was validated with experimental results was used to analyze the injection characteristics of each hole. The validation was conducted by comparing experiment and simulation injection rate results, acquired simultaneously from all the holes of the injector and the model. The fuel flow rates of the lower layered holes are higher than those of the upper layered holes. Two different needle eccentricity models were established. The first model only included the lateral displacement of the needle during needle lift. The needle reached maximum displacement at full needle lift. The second model considered the needle inelastic deformation into consideration. The needle radially displaces and glides along with the needle seat surface during needle lift. When the eccentricity reached maximum in the radial direction, the needle began to lift upwards vertically. The differences in injection characteristics under the different eccentricity models were apparent. The results indicated that the cycle injection quantity, fuel injection rate and cavitation of each hole were affected during the initial lifting stages of the needle lift. As the eccentricity of the needle increases, the injection rate uniformity from the nozzle hole deteriorates. The result showed that the upper layered holes were affected by the needle eccentricity during needle lift.

scholarly journals Quasi-two-dimensional approximation for numerical simulation of flows in engine ducts

2019 ◽  
Author(s):  
V. Vlasenko ◽  
A. Shiryaeva
Keyword(s):  
High Speed ◽  
Fuel Injection ◽  
Three Dimensional ◽  
Preliminary Design ◽  
Two Dimensional ◽  
Combustion Chambers ◽  
New Approach ◽  
One Dimensional ◽  
Dimensional Approximation ◽  
3D Flows

New quasi-two-dimensional (2.5D) approach to description of three-dimensional (3D) flows in ducts is proposed. It generalizes quasi-one-dimensional (quasi-1D, 1.5D) theories. Calculations are performed in the (x; y) plane, but variable width of duct in the z direction is taken into account. Derivation of 2.5D approximation equations is given. Tests for verification of 2.5D calculations are proposed. Parametrical 2.5D calculations of flow with hydrogen combustion in an elliptical combustor of a high-speed aircraft, investigated within HEXAFLY-INT international project, are described. Optimal scheme of fuel injection is found and explained. For one regime, 2.5D and 3D calculations are compared. The new approach is recommended for use during preliminary design of combustion chambers.

Dynamic Analysis of Large-Scale Power House

2012 ◽  
Vol 446-449 ◽  
pp. 837-840
Author(s):  
Yu Zhao ◽  
Shu Fang Yuan ◽  
Jian Wei Zhang
Keyword(s):  
Finite Element ◽  
Dynamic Characteristics ◽  
Large Scale ◽  
Three Dimensional ◽  
Dynamic Responses ◽  
Dynamic Loads ◽  
Element Analysis ◽  
Power House ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element

The underwater structure of power house is major structure under the dynamic loads of unit. The vibration problem is very common in operation. So the structures should have sufficient stiffness to resist dynamic loads of unit. This paper establishes three-dimensional finite element models with finite element analysis software—ANSYS. Dynamic characteristics of the power house and dynamic responses of structure under earthquake are analyzed. The results of the computation show that fluid-solid coupling may be ignored when studying dynamic characteristics of structures of the underground power house.

Model Simulation and Design Optimization of a Can Combustor with Methane/Syngas Fuels for a Micro Gas Turbine

2018 ◽  
Vol 0 (0) ◽  
Author(s):  
Chi-Rong Liu ◽  
Ming-Tsung Sun ◽  
Hsin-Yi Shih
Keyword(s):  
Gas Turbine ◽  
Turbulent Flows ◽  
Film Cooling ◽  
Fuel Injection ◽  
Model Simulation ◽  
Combustion Process ◽  
Three Dimensional ◽  
Future Application ◽  
Detailed Chemical Kinetics ◽  
Micro Gas Turbine

Abstract The design and model simulation of a can combustor has been made for future syngas combustion application in a micro gas turbine. An improved design of the combustor is studied in this work, where a new fuel injection strategy and film cooling are employed. The simulation of the combustor is conducted by a computational model, which consists of three-dimensional, compressible k-ε model for turbulent flows and PPDF (Presumed Probability Density Function) model for combustion process invoking a laminar flamelet assumption generated by detailed chemical kinetics from GRI 3.0. Thermal and prompt NOx mechanisms are adopted to predict the NO formation. The modeling results indicated that the high temperature flames are stabilized in the center of the primary zone by radially injecting the fuel inward. The exit temperatures of the modified can combustor drop and exhibit a more uniform distribution by coupling film cooling, resulting in a low pattern factor. The combustion characteristics were then investigated and the optimization procedures of the fuel compositions and fuel flow rates were developed for future application of methane/syngas fuels in the micro gas turbine.

Multiscale Modeling of Dynamic Characteristics of Carbon Nanotube Reinforced Nanocomposites

NANO ◽  
2016 ◽  
Vol 11 (07) ◽  
pp. 1650083 ◽  
Author(s):  
Sachin O. Gajbhiye ◽  
S. P. Singh
Keyword(s):  
Carbon Nanotube ◽  
Dynamic Characteristics ◽  
Matrix Material ◽  
Three Dimensional ◽  
Vacancy Defect ◽  
Nanocomposite Material ◽  
Phase Lag ◽  
Rate Dependent ◽  
Carbon Carbon Bond ◽  
The Matrix

A unique atomic structure of carbon nanotube unveils outstanding properties. This makes it potentially highly valued reinforcing material to strengthen composite materials. The methodology is established in this research paper to investigate the static and dynamic characteristics of the nanocomposites. Repol polypropylene H110MA is used as a matrix material along with the different percentages of single-walled carbon nanotubes (SWCNTs). A concept of representative volume element (RVE) is considered to study the various properties of the nanocomposite material. The carbon–carbon bond of nanotube is modeled using Tersoff–Brenner potential and represented by space frame element. The matrix material properties are tested in the laboratory which are further used to model it and represented by three-dimensional continuum elements. The interaction between nanotube and polymer matrix is modeled using “Lennard–Jones 6-12” potential represented by nonlinear spring elements. The effect of reinforcement, chirality, % volume of SWCNT, atomic vacancy defect and Stone–Wales defect on the properties of nanocomposite are investigated. To see the effect of reinforcement, the eigenvalues of the RVE are extracted for different boundary conditions. The viscoplastic behavior of the matrix material is considered and the rate-dependent characteristics of the nanocomposite are studied. The damping property of the nanocomposite material is also investigated based on the phase lag between stress and strain field by applying harmonic strain at different frequencies.

Static and Dynamic Characteristics Analysis of HTM125 Milling Complex Machining Center Column

2014 ◽  
Vol 1077 ◽  
pp. 191-196
Author(s):  
Yu Hou Wu ◽  
Yu Hang Ren ◽  
De Hong Zhao ◽  
Feng Lu
Keyword(s):  
Dynamic Characteristics ◽  
Three Dimensional ◽  
Mode Shapes ◽  
Three Dimensional Model ◽  
Static And Dynamic Characteristics ◽  
Machining Center ◽  
Characteristics Analysis ◽  
Object Of Study ◽  
Five Axis ◽  
Dynamic Characteristics Analysis

The column of heavy double turret five-axis horizontal milling complex machining center is taken as the object of study. Solidworks is used to establish three-dimensional model of milling machining center column, the established modal is be imported into ANSYS Workbench for static and dynamic characteristics analysis. First, by comparing the column deformation, the stress and strain under no-load and load conditions, which is concluded that column design is too conservative and be optimized. Secondly, the modal analysis was carried out on the column, which provides a theoretical basis for the optimization of the column by getting the first six natural frequencies and mode shapes of cloud.

scholarly journals Vortex flow and cavitation in diesel injector nozzles

2008 ◽  
Vol 610 ◽  
pp. 195-215 ◽  
Author(s):  
A. ANDRIOTIS ◽  
M. GAVAISES ◽  
C. ARCOUMANIS
Keyword(s):  
High Speed ◽  
Fuel Injection ◽  
Dimensional Space ◽  
Three Dimensional ◽  
Flow Distribution ◽  
Fuel Injector ◽  
Flowing Liquid ◽  
Injection Quantity ◽  
Dimensional Reconstruction ◽  
Real Size

Flow visualization as well as three-dimensional cavitating flow simulations have been employed for characterizing the formation of cavitation inside transparent replicas of fuel injector valves used in low-speed two-stroke diesel engines. The designs tested have incorporated five-hole nozzles with cylindrical as well as tapered holes operating at different fixed needle lift positions. High-speed images have revealed the formation of an unsteady vapour structure upstream of the injection holes inside the nozzle volume, which is referred to as ‘string-cavitation’. Computation of the flow distribution and combination with three-dimensional reconstruction of the location of the strings inside the nozzle volume has revealed that strings are found at the core of recirculation zones; they originate either from pre-existing cavitation sites forming at sharp corners inside the nozzle where the pressure falls below the vapour pressure of the flowing liquid, or even from suction of outside air downstream of the hole exit. Processing of the acquired images has allowed estimation of the mean location and probability of appearance of the cavitating strings in the three-dimensional space as a function of needle lift, cavitation and Reynolds number. The frequency of appearance of the strings has been correlated with the Strouhal number of the vortices developing inside the sac volume; the latter has been found to be a function of needle lift and hole shape. The presence of strings has significantly affected the flow conditions at the nozzle exit, influencing the injected spray. The cavitation structures formed inside the injection holes are significantly altered by the presence of cavitation strings and are jointly responsible for up to 10% variation in the instantaneous fuel injection quantity. Extrapolation using model predictions for real-size injectors operating at realistic injection pressures indicates that cavitation strings are expected to appear within the time scales of typical injection events, implying significant hole-to-hole and cycle-to-cycle variations during the corresponding spray development.

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