Cryogenic Fluid Dynamic Response of Swirl Injector to External Forcing at Supercritical Conditions

2009 ◽  
Author(s):  
Hongfa Huo ◽  
Nan Zong ◽  
Vigor Yang
Keyword(s):  
Dynamic Response ◽  
Fluid Dynamic ◽  
External Forcing ◽  
Supercritical Conditions ◽  
Cryogenic Fluid ◽  
Swirl Injector

scholarly journals Fluid Dynamic Response of the Russia Seismically Differing Regions to the Global Geodynamics Processes

2012 ◽  
Vol 03 (04) ◽  
pp. 767-771 ◽  
Author(s):  
Valera P. Rudakov ◽  
Pavel P. Firstov ◽  
Vladislav V. Tsyplakov
Keyword(s):  
Dynamic Response ◽  
Fluid Dynamic ◽  
Global Geodynamics

The Role of Simulation in the Development of a Fast-Actuation Solenoid C.R. Injection System

2004 ◽  
Author(s):  
Gian Marco Bianchi ◽  
Piero Pelloni ◽  
Giovanni Osbat ◽  
Marco Parotto ◽  
Rita Di Gioia ◽  
...  
Keyword(s):  
Dynamic Response ◽  
Control Strategies ◽  
Fluid Dynamic ◽  
Numerical Approach ◽  
Linear Analysis ◽  
Operating Conditions ◽  
System Model ◽  
Injection System ◽  
Multiple Injection ◽  
Pressure Regulator

Upcoming Euro 4 and Euro 5 emission standards are increasing efforts on injection system developments in order to improve mixture quality and combustion efficiency. The target features of advanced injection system are related to their capability of operating multiple injection with a precise control of amount of fuel injected, low cycle-by-cycle variability and life drift, within flexible strategies. In order to accomplish this task, performance must be optimised since injection system concept development by acting on. The extensive use of numerical approach has been identified as a necessary integration to experiments in order to put on the market high quality injection system accomplishing strict engine control strategies. The modelling approach allows focusing the experimental campaign only on critical issues saving time and costs, furthermore it is possible to deeply understand inner phenomena that cannot be measured. The lump/ID model of the whole system built into the AMESim® code was presented in previous works: particular attention was devoted in the simulation of the electromagnetic circuits, actual fluid-dynamic forces acting on needle surfaces and discharge coefficients, evaluated by means 3D-CFD simulations. In order to assess new injection system dynamic response under multiple injection strategies reproducing actual engine operating conditions it is necessary to find to proper model settings. In this work the integration between the injector and the system model, which comprehends the pump, the pressure regulator, the rail and the connecting-pipes, will be presented. For reproducing the dynamic response of he whole system will be followed a step-by-step approach in order to prevent modelling inaccuracies. Firstly will be presented the linear analysis results performed in order to find injection system own natural frequencies. Secondly based on linear analysis results will be found proper injection system model settings for predicting dynamic response to external excitations, such as pump perturbations, pressure regulator dynamics and injection pulses. Thirdly experimental results in terms of instantaneous flow rate and integrated injected volume for different operating conditions will be presented in order to highlight the capability of the modelling methodology in addressing the new injection system design.

Effect of Baffle Design Parameters on Fluid Dynamic Response of a Coal Classifier

2014 ◽  
Vol 3 (0) ◽  
pp. 15
Author(s):  
Hamid Khoshdast ◽  
Hami Khoshdast ◽  
Vahideh Shojaei
Keyword(s):  
Dynamic Response ◽  
Fluid Dynamic ◽  
Design Parameters

Role of Inlet Boundary Conditions on Fuel-Air Mixing at Supercritical Conditions

2020 ◽  
Author(s):  
Zachary Harris ◽  
Joshua Bittle ◽  
Ajay Agrawal
Keyword(s):  
Experimental Data ◽  
Boundary Conditions ◽  
Gas Turbines ◽  
Alternative Fuels ◽  
Fuel Injection ◽  
Fluid Dynamic ◽  
Supercritical Conditions ◽  
Complex Interactions ◽  
Significant Research ◽  
Air Mixing

Abstract Advanced engine design and alternative fuels present the possibility of fuel injection at purely supercritical conditions in diesel engines and gas turbines. The complex interactions that govern this phenomenon still need significant research for reliable modeling efforts. Boundary conditions for fuel injection are critical to accurate simulation. However, the flow inside the injector itself is often omitted to reduce the computational efforts, and thus, velocity, mass flux, or total pressure is specified at the injector exit (or domain inlet), often with an assumed top hat profile and assumed turbulence levels. Past studies have shown that such simplified inlet boundary treatment has minimal effects on the results for fuel injection in the compressed liquid phase. However, the validity of this approach at supercritical fuel injection conditions has not been assessed so far. In this study, comprehensive real-gas and binary fluid mixing models have been implemented for computational fluid dynamic (CFD) analysis of fuel-air mixing at supercritical conditions. The model is verified using prior CFD results from the literature. Next, the model is used to investigate the effects of the shape of axial velocity and mass fraction profiles at the inlet boundary with the goal to improve the comparison of predictions to experimental data. Results show that the boundary conditions have a significant effect on the predictions, and none of the cases match precisely with experimental data. The study reveals that the physical location of the inlet boundary might be difficult to infer correctly from the experiments and highlights the need for high-quality, repeatable measurements at supercritical conditions to support the development of relevant high-fidelity models for fuel-air mixing.

ROLE OF INLET BOUNDARY CONDITIONS ON FUEL-AIR MIXING AT SUPERCRITICAL CONDITIONS

2021 ◽  
pp. 1-22
Author(s):  
Zachary Harris ◽  
Joshua Bittle ◽  
Ajay Agrawal
Keyword(s):  
Experimental Data ◽  
Boundary Conditions ◽  
Gas Turbines ◽  
Alternative Fuels ◽  
Fuel Injection ◽  
Fluid Dynamic ◽  
Supercritical Conditions ◽  
Complex Interactions ◽  
Significant Research ◽  
Air Mixing

Abstract Advanced engine design and alternative fuels present the possibility of fuel injection at purely supercritical conditions in diesel engines and gas turbines. The complex interactions that govern this phenomenon still need significant research, particularly the boundary conditions for fuel injection are critical for accurate simulation. However, the flow inside the injector itself is often omitted to reduce the computational efforts, and thus, velocity, mass flux, or total pressure is specified at the injector exit (or domain inlet), often with simplified velocity profiles and turbulence levels. This simplified inlet boundary treatment has minimal effects on results for conventional fuel injection conditions, however, the validity of this approach at supercritical conditions has not been assessed. Comprehensive real-gas and binary fluid mixing models have been implemented for computational fluid dynamic (CFD) analysis of fuel-air mixing at supercritical conditions. The model is verified using prior CFD results from the literature. The model is used to investigate the effects of the shape of axial velocity and mass fraction profiles at the inlet boundary with the goal to improve the comparison of predictions to experimental data. Results show that the boundary conditions have a significant effect on the predictions, and none of the cases match precisely with experimental data. The study reveals that the physical location of the inlet boundary might be difficult to infer correctly from the experiments and highlights the need for high-quality, repeatable measurements at supercritical conditions to support the development of relevant high-fidelity models for fuel-air mixing.

Development of a coupled numerical model for the interaction between transient fluid slosh and tank wagon vibration

2018 ◽  
Vol 233 (3) ◽  
pp. 568-582 ◽  
Author(s):  
Ahmad Rahmati-Alaei ◽  
Majid Sharavi ◽  
Masoud Samadian Zakaria
Keyword(s):  
Dynamic Response ◽  
Stokes Equations ◽  
Fluid Dynamic ◽  
Nonlinear Differential Equations ◽  
Coupled Model ◽  
Longitudinal Direction ◽  
Rolling Contact ◽  
Cross Sectional ◽  
Response Characteristics ◽  
Dynamic Response Characteristics

In this paper, a coupled model is developed to evaluate the effect of transient fluid slosh on the railway tank wagon dynamic vice versa. This model has computational complexity in solving the Navier–Stokes equations and nonlinear differential equations of tank wagon vibration with nonlinear wheel–rail contact. The coupled model can be used as an effective and robust tool compared to simplified models for assessing the stability of tank wagon. The transient fluid slosh model is analysed using the computational fluid dynamic method combined with the volume of fluid technique. The tank wagon dynamic model is solved using the fourth-order Runge–Kutta method based on the 19 degrees of freedom model with longitudinal, vertical, roll and pitch vibrations. The wheel–rail contact is considered according to nonlinear Hertzian and Kalker linear rolling contact theories. The fluid slosh model is validated using experimental data. The dynamic response characteristics of the partially filled railway tank wagon are investigated under straight-line braking manoeuvre using the coupled model. The results obtained from a parametric study, including the cross sectional shape and the filled volume show that the modified-oval cross section improves the dynamic response characteristics, which are attributed to its lower fluid's centre of gravity coordinate in the longitudinal direction and low lateral moment transfer of the fluid.

Dynamic characteristics of a cryogenic nitrogen swirl injector under supercritical conditions

2017 ◽  
Vol 67 ◽  
pp. 398-411 ◽  
Author(s):  
Jeongseok Kang ◽  
Junyoung Heo ◽  
Hong-Gye Sung ◽  
Youngbin Yoon
Keyword(s):  
Dynamic Characteristics ◽  
Supercritical Conditions ◽  
Swirl Injector
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