A Technological Effect Modeling on Complex Turbomachinery Applications With an Overset Grid Numerical Method

2014 ◽  
Vol 136 (10) ◽  
Author(s):  
Lionel Castillon ◽  
Gilles Billonnet ◽  
Jacques Riou ◽  
Stéphanie Péron ◽  
Christophe Benoit

This paper presents an overview of numerical simulations performed at ONERA on turbomachinery configurations which include technological effects, such as tip clearance, hub disk leakage, circumferential and noncircumferential casing treatments (CTs), blade fillets, and cooling holes. An overset grid approach (Chimera technique) is used to simulate these geometrical effects with ONERA's structured computational fluid dynamics (CFD) solver elsA. Calculations performed on the different configurations enable to quantify the impact of these technological effects on the flow solution.

2021 ◽  
Author(s):  
Sanaz Dianat

The research paper investigates the impact of a window’s exterior air film on the assembly temperature. The exterior air film constitutes a vital portion of a window’s insulating values. The air film increases the temperature of the window exterior pane to a temperature above ambient temperature. The air film also rises the interior glass temperature and reduces the heat transfer from the interior surface. According to computational fluid dynamics (CFD), the air film is removed in windy conditions, decreasing the window temperature on the outside as well as on the inside. The idea behind the project is to carry out an experimental procedure on three different windows to validate the CFD results, which indicates the effect of various wind speeds. Keyword: Exterior air film, computational fluid dynamics, window assembly, wind speed


2021 ◽  
Author(s):  
Sanaz Dianat

The research paper investigates the impact of a window’s exterior air film on the assembly temperature. The exterior air film constitutes a vital portion of a window’s insulating values. The air film increases the temperature of the window exterior pane to a temperature above ambient temperature. The air film also rises the interior glass temperature and reduces the heat transfer from the interior surface. According to computational fluid dynamics (CFD), the air film is removed in windy conditions, decreasing the window temperature on the outside as well as on the inside. The idea behind the project is to carry out an experimental procedure on three different windows to validate the CFD results, which indicates the effect of various wind speeds. Keyword: Exterior air film, computational fluid dynamics, window assembly, wind speed


Energies ◽  
2018 ◽  
Vol 12 (1) ◽  
pp. 41
Author(s):  
Siong Lee ◽  
Thomas Choong ◽  
Luqman Abdullah ◽  
Mus’ab Abdul Razak ◽  
Zhen Ban

For a gas-liquid separator sizing, many engineers have neglected the flow pattern of incoming fluids. The impact of inlet slug flow which impeded onto the separator’s liquid phase will cause a separator fails to perform when sloshing happened in the separator. To date, the study on verifying the impact of inlet slug flow in a separator remains limited. In this paper, the impact of inlet momentum and inlet slug flow on the hydrodynamics in a separator for cases without an inlet device were investigated. The experimental and Computational Fluid Dynamics (CFD) results of cavity formation and sloshing occurrence in the separator in this study were compared. A User Defined Function (UDF) was used to describe the inlet slug flow at the separator inlet. Inlet slug flow occurred at inlet momentum from 200 to 1000 Pa, and sloshing occurred in the separator at 1000 Pa. Both experimental and simulated results showed similar phenomena.


Author(s):  
Tobias Mayenberger ◽  
Hans-Peter Kau ◽  
Giovanni Brignole

In this study endwall treatments, which are integrated into an abradable liner, are used to reduce the liner solidity, defined by the volumetric proportion between endwall treatments and solid casing. Consequently the milled off amount of liner material during the rubbing process is decreased. The mechanical stresses in the rotor blades are thus supposed to be reduced, so that liner materials with higher strength can be used or additional blade tip coatings are dispensable. Accordingly, the purpose of the present study was to develop geometries of endwall treatments, which reduce the liner solidity as much as possible without degrading the stage performance of the test compressor. The focus of the work lies exclusively on the aerodynamics. Investigations were made by steady and unsteady computational fluid dynamics on a transonic single stage axial compressor with two different tip clearance sizes (0.64%/1.28% span). The developed configurations resemble casing treatments, comparable to axial slots and circumferential grooves, which are adapted to the specific tasks of liners. Solidity could be reduced by as much as 29% with negligible efficiency degradation for small tip gaps and increased efficiencies for large tip clearances.


Author(s):  
Sotos C. Generalis ◽  
Gregory M Cartland Glover

Earlier investigations (Cartland Glover et al., 2004) into the use of computational fluid dynamics (CFD) for the modelling of gas-liquid and gas-liquid-solid flow allowed a simple biochemical reaction model to be implemented. A single plane mesh was used to represent the transport and reaction of molasses, the mould Aspergillus niger and citric acid in a bubble column with a height to diameter aspect ratio of 20:1. Two specific growth rates were used to examine the impact that biomass growth had on the local solids concentration and the effect this had on the local hydrodynamics of the bubble column.


Author(s):  
Mai Hanna Shahda ◽  
Mahmod Alfattamah ◽  
Youssef Johar

The research aims to predict the efficiency of capturing the soot particles generated by the diesel generator within the Hydro Cyclone by conducting the applied study using the Computational Fluid Dynamics (CFD) application through modeling and simulation of the turbulent flow within the Hydro Cyclone using SOLIDWORKS Flow Simulation. The ability to predict the impact of such flows on your product performance is time consuming and costly without some form of simulation tools...SOLIDWORKS Flow Simulation uses Computational Fluid Dynamics (CFD) analysis to enable quick, efficient simulation of fluid flow and can easily calculate fluid forces and help the designer to understand the impact of a liquid or gas on product performance and comparing the results with experimental reality. In this research, the engineering simulation confirmed the importance of using Hydro Cyclone in the capture of diesel soot particles by an error rate of only 4% compared to experimental reality.


2021 ◽  
Author(s):  
Wen Nie ◽  
Xiaofei Liu ◽  
Chengyi Liu ◽  
Lidian Guo ◽  
Yun Hua

Abstract To analyze the impact of exhaust emissions from mine hydraulic support transporters on the roadway environment. In this paper, the dispersion distribution of diesel exhaust pollutant during the functioning of a hydraulic support transporters were all-round simulated by Dynamic Mesh of Computational Fluid Dynamics. More specifically, the dispersion and distribution of the main exhaust pollutants CO, HC, and NOx emitted by vehicles under the influence of the roadway wind flow were simulated with computational fluid dynamics (CFD) and the dispersion of exhaust pollutants from hydraulic support transporters during multiple driving phases in an alleyway (from hauling in material, unloading at idle speed, to driving off with no load) was predicted. The simulation results show that the exhaust pollutants emitted during the movement of hydraulic support transporters can pollute the roadway environment and negatively affect gas monitoring devices in the roadway. Therefore, coal mining enterprises should optimize the ventilation design scheme to improve the roadway environment: they should increase the ventilation volume to dilute the emitted pollutants; in addition, the locations of underground gas monitoring devices should be adjusted to avoid interference from exhaust pollutants emitted by vehicles. This paper provides a theoretical basis for the preliminary investigation of the dispersion and transportation characteristics of exhaust pollutants emitted by vehicles in roadways, the research in this paper is of guiding significance to reduce the inhalation of the diesel exhaust pollutants of the miners and reduce the probability of suffering from occupational diseases.


Author(s):  
Vibhor Mehrotra ◽  
Philip Diwakar ◽  
Rimon Vallavanatt

Industrial application of Computational Fluid Dynamics (CFD) requires the solution of complex fluid-flow problems in conjunction with equipment design, process and product development and optimization. For the successful solution of these problems, a high degree of coordination between industrial CFD engineers, software developers, consultants and academic scientists is necessary. In a refinery, CFD may be applied to a variety of problems. In particular, combustion, flames, flares and chemical reaction are of interest because of the physics and the complex nature of the process. Two applications are presented in this paper to demonstrate the use of CFD modeling for improving furnace operations. The first concerns improvements in reboiler operation by changing burner arrangement. A three-burner arrangement has resulted in tube burnout in the past. CFD modeling suggested a four-burner arrangement is better. The recommendation was accepted and implemented by the refinery in 2002. Feedback from the refinery suggests a much cooler furnace operation is observed in the field. The second application concerns predicting Coker furnace operation of as yet uninstalled heater. The Coker radiant section is modeled with 4 burners. Predicting the impact of burner-burner interaction on the radiant heat flux helps in determining the time period for decoke. Several mitigation steps are suggested to increase the run length between decoking intervals. Further recommendation to create a balanced heat flux profile is provided.


Author(s):  
Rajani Satti ◽  
Narasimha Rao Pillalamarri ◽  
Eckard Scholz

In this study, the application of computational fluid dynamics (CFD) is explored to predict the performance characteristics in a typical single-stage downhole turbine. The single-stage turbine model utilized for this study consists of a stator and a rotor. A finite-volume based CFD approach was implemented to simulate the complex flow field around the turbine. The analysis is based on transient, three-dimensional, isothermal turbulent flow in an incompressible fluid system. The inlet flow rates and angular velocity of the rotor were varied to encompass the operating regime. Comparison with experimental data revealed excellent agreement, proving reliability of the model in predicting the performance characteristics. Motivated by the successful model validation, a parametric study (considering blade tip clearance and blade count) was also conducted to understand the effects of the design parameters on the performance of the turbine. Detailed flow visualizations and efficiency calculations were also done to provide further insight into the overall performance of the turbine. As part of the present study, significant efforts were also spent in the following areas: standardization of CFD methodology and assessment of commercial software to develop an integrated CFD-driven design process.


Sign in / Sign up

Export Citation Format

Share Document