Comprehensive Simulation and Optimization of an Ethylene Dichloride Cracker Based on the One-Dimensional Lobo–Evans Method and Computational Fluid Dynamics

2013 ◽  
Vol 52 (2) ◽  
pp. 645-657 ◽  
Author(s):  
Chaochun Li ◽  
Guihua Hu ◽  
Weimin Zhong ◽  
Hui Cheng ◽  
Wenli Du ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Ethylene Dichloride ◽  
One Dimensional ◽  
Simulation And Optimization ◽  
The One

One-dimensional modeling for tip clearance leakage vortex trajectory and stall-onset prediction in subsonic centrifugal impellers

2019 ◽  
Vol 234 (3) ◽  
pp. 263-282
Author(s):  
Chaowei Zhang ◽  
Xuezhi Dong ◽  
Xiyang Liu ◽  
Qing Gao ◽  
Chunqing Tan ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Tip Clearance ◽  
Leakage Flow ◽  
Tip Leakage Flow ◽  
Tip Leakage Vortex ◽  
One Dimensional ◽  
Tip Leakage ◽  
Onset Point ◽  
The One

Two one-dimensional models are established for the tip leakage vortex trajectory and rotating stall-onset point prediction respectively for subsonic centrifugal impellers. The goal of modeling is to supply an effective estimation strategy of the stall-onset point for use in the one-dimensional performance prediction stage. The tip leakage vortex trajectory prediction is a critical part of the stall-onset prediction. The proposed one-dimensional model (one-dimensional tip leakage vortex trajectory model) to predict the tip leakage vortex trajectory is based on blade loading, i.e. the velocity difference between the pressure and suction surfaces. The loading function considers the effect of radial rotation, blade turning, and passage width variation. Compared with the computational fluid dynamics results, the current model shows reasonable accuracy, with an average relative error below 12.35%. The one-dimensional prediction model (Model II) is developed to determine the stall-onset point, where the interface between the tip leakage flow and the main flow spills from the blade leading edge. In this model, the momentum balance analysis is applied to identify the position of the interface. The parameter of the tip leakage vortex trajectory in Model II is determined by one-dimensional tip leakage vortex trajectory model. The effective origin of the tip leakage flow is correlated with the rotational speed and tip clearance. The effectiveness of Model II is validated with the experimental and computational fluid dynamics results using three impellers. Compared with the conventional model (Model I), Model II shows better accuracy, with a maximum error of about 7.42%.

Network analysis of a coolant flow performance for the combined impingement and film cooled first-stage of high pressure gas turbine nozzle guide vane

2018 ◽  
Vol 233 (6) ◽  
pp. 1977-1989 ◽  
Author(s):  
Pol Reddy Kukutla ◽  
BVSSS Prasad
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Guide Vane ◽  
System Level ◽  
One Dimensional ◽  
Fluid Network ◽  
Nozzle Guide Vane ◽  
Dimensional Simulation ◽  
The One ◽  
Nozzle Guide

The present paper describes a system-level thermo-fluid network analysis for the secondary air system analysis of a typically film-cooled nozzle guide vane with multiple actions of jet impingement. The one-dimensional simulation was done with the help of the commercially available Flownex 2015 software. The system-level thermo-fluid network results were validated with both the computational fluid dynamics results and experimentally available literature. The entire nozzle guide vane geometry was first mapped to a thermo-fluid network model and the pressure conditions at different nodes. The discharge and heat transfer coefficients obtained from the Ansys FLUENT were specified as inputs to the thermo-fluid network model. The results show that the one-dimensional simulation of the coolant mass flow rates and jet Nusselt number values are in good agreement with the three-dimensional computational fluid dynamics results.

scholarly journals A zonal approach for estimating pressure ratio at compressor extreme off-design conditions

2018 ◽  
Vol 20 (4) ◽  
pp. 393-404 ◽  
Author(s):  
José Galindo ◽  
Roberto Navarro ◽  
Luis Miguel García-Cuevas ◽  
Daniel Tarí ◽  
Hadi Tartoussi ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
High Speed ◽  
Internal Combustion Engines ◽  
Pressure Ratio ◽  
Internal Combustion ◽  
Operating Conditions ◽  
Combustion Engines ◽  
One Dimensional ◽  
Performance Map

Zero-dimensional/one-dimensional computational fluid dynamics codes are used to simulate the performance of complete internal combustion engines. In such codes, the operation of a turbocharger compressor is usually addressed employing its performance map. However, simulation of engine transients may drive the compressor to work at operating conditions outside the region provided by the manufacturer map. Therefore, a method is required to extrapolate the performance map to extended off-design conditions. This work examines several extrapolating methods at the different off-design regions, namely, low-pressure ratio zone, low-speed zone and high-speed zone. The accuracy of the methods is assessed with the aid of compressor extreme off-design measurements. In this way, the best method is selected for each region and the manufacturer map is used in design conditions, resulting in a zonal extrapolating approach aiming to preserve accuracy. The transitions between extrapolated zones are corrected, avoiding discontinuities and instabilities.

Collaborative Computing Methods for One-Dimensional and Three-Dimensional Problems of Computational Fluid Dynamics

2020 ◽  
Vol 12 (4) ◽  
pp. 536-545
Author(s):  
A. V. Yalozo ◽  
A. S. Kozelkov ◽  
A. A. Kurkin ◽  
V. V. Kurulin ◽  
I. L. Materova ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Three Dimensional ◽  
Computing Methods ◽  
Collaborative Computing ◽  
One Dimensional

Analysis of Enclosure Fires Using the Isis-3D™ CFD Engineering Analysis Code

2004 ◽  
Author(s):  
Ahti Suo-Anttila ◽  
K. C. Wagner ◽  
Miles Greiner
Keyword(s):  
Heat Transfer ◽  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Fuel Vapor ◽  
Gaseous Species ◽  
Typical Application ◽  
One Dimensional ◽  
Fast Running ◽  
Engineering Level ◽  
Fire Experiments

The Isis-3D™ computational fluid dynamics (CFD) code is currently under development for the Defense Threat Reduction Agency (DTRA) as a tool for risk assessment and engineering level analysis. It is designed to provide reasonably accurate estimates of the total heat transfer to objects from large fires under a variety of circumstances, predict the medium characteristics such as temperature and species concentration distributions, and use fairly short computer turnaround times. Isis-3D™ models liquid fuel evaporation, transport of fuel vapor, oxygen and other relevant species, reaction and heat release, and soot and other gaseous species formation, destruction, and transport. It models diffuse radiation within the fire and view factor radiation from the fire edge to nearby objects and the surroundings. One-dimensional transient sub-grid modules are also embedded into Isis-3D™. Either or both “ends” of each module are coupled to the flowing medium region, or objects within the three-dimensional medium. These modules allow the code to calculate the one-dimensional response of simple solid objects to the fire environment without affecting the computational fluid dynamics time step. The sub-grid modules can include thermal conduction, convection, momentum, mass, and species exchange. For example, they can be used to simulate the decomposition of organic materials (e.g. burning wood), the evaporation of liquid fuels, and the injection of gases, such as fire suppressants. Fast-running radiation heat transfer and chemical reaction models embedded in the code are designed to enable it to give engineering-level accurate results for large-fire heat transfer even when relatively coarse computational grids are employed. Low to medium level resolution Isis-3D™ simulations (less than 60,000 nodes) are relatively fast running and hence well suited for risk assessments, parametric scenario variations, and engineering level analyses. This paper includes comparisons of Isis-3D™ predictions to two enclosure fire experiments, the classical Steckler room fire experiments and the Sandia National Laboratories (SNL) Igloo enclosure fires. The Steckler fire experiments were steady state fires with a fixed heat input. The SNL Igloo tests were larger scale, unsteady fuel pan fires. Comparisons of the predicted temperature distributions within the enclosures for several tests are shown. A typical application of Isis-3D™ is also illustrated wherein the CO2 fire suppressant distribution within the cable room of a nuclear power plant is predicted as a function of time.

scholarly journals A Study on the Efficient Method for the Solution of the Saha Equation in the Numerical Simulation of Capillary Discharge

2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Hengzhu Liu ◽  
Cheng Wu ◽  
Fengjiang An ◽  
Shasha Liao
Keyword(s):  
Fluid Dynamics ◽  
Numerical Simulation ◽  
Computational Fluid Dynamics ◽  
Transport Coefficients ◽  
Capillary Discharge ◽  
Dimensional Problem ◽  
Initial Value ◽  
One Dimensional ◽  
Saha Equation ◽  
Dynamics Problems

In the numerical simulation of capillary discharge for the Electrothermal (ET) or ET-chemical (ETC) launch system, one needs to solve the Saha equation to determine the composition of plasma for the transport coefficients. This would cause a relatively longer simulation runtime compared with conventional computational fluid dynamics problems. In this paper, the relatively difficult multidimensional problem of solving the Saha equation is transformed into a one-dimensional problem in the simulation of capillary discharge by constructing an iteration equation about temperature. A coefficient is introduced to ensure the convergence of this iteration equation. In order to improve the computational efficiency, this coefficient is further optimized and the methods of setting the iteration initial value dynamically are introduced. Several simulation tests are conducted to study the performance of these two methods. The results show that the simulation runtime could be significantly reduced with the methods presented in this paper.

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