Hydrodynamics and Hydroacoustics Investigation of a Blade Profile in a Hubless Propeller System Based on a Hybrid Approach

2019 ◽  
Vol 105 (4) ◽  
pp. 600-615
Author(s):  
Hoshang Sultani ◽  
Max Hieke ◽  
Otto von Estorff ◽  
Matthias Witte ◽  
Frank-Hendrik Wurm
Keyword(s):  
Cfd Simulation ◽  
Fluid Dynamic ◽  
Hybrid Approach ◽  
Flow Simulation ◽  
Detached Eddy Simulation ◽  
Blade Profile ◽  
Eddy Simulation ◽  
System A ◽  
Pressure Fields ◽  
Experimental Hydrodynamics

The scope of the paper is the investigation of the hydrodynamic and hydroacoustic characteristic of a blade profile within a hubless propeller system. A hybrid procedure was applied in which the flow simulation results in terms of velocity and pressure fields were used as source terms for the hydroacoustics calculations. The Computational Fluid Dynamic (CFD) simulation of the complex 3D system was done using a scale resolving Detached Eddy Simulation (DES). The calculation of the acoustics was carried out using the Expansion about Incompressible Flow (EIF) approach. For the spatial discretization of the EIF equations the Finite Volume Moving Least Squares (FV-MLS) method was used. This method has promising features especially in the application of unstructured meshes. A first verification of the acoustic model is presented. For the validation of the used numerical methods extensive experimental hydrodynamics and hydroacoustics investigations of the hubless propeller system were carried out.

scholarly journals Zonal Detached Eddy Simulation of the Fan-OGV Stage of a Modern Turbofan Engine

2020 ◽  
Author(s):  
Benjamin François ◽  
Raphaël Barrier ◽  
Cyril Polacsek
Keyword(s):  
Statistical Convergence ◽  
Hybrid Approach ◽  
Broadband Noise ◽  
Detached Eddy Simulation ◽  
Turbofan Engine ◽  
The Core ◽  
Eddy Simulation ◽  
Gap Flow ◽  
Radial Profiles ◽  
Radial Evolution

Abstract The present article deals with the Zonal Detached Eddy Simulation of the fan module of a modern turbofan engine. The fan module, tested at the AneCom facility, is equipped with rotating fan blades and stationary outlet guide vanes (OGV). The simulation was performed to capture the interaction of the turbulent fan wakes with the OGV walls. The final goal of this simulation is the prediction of the associated broadband noise, not adressed here. In this paper, only the aerodynamic aspects are treated. The simulation relies on a hybrid RANS/LES approach with a zonal strategy: the core airflow is treated in RANS while the bypass airflow is solved with the hybrid approach. Mesh criteria meeting both RANS/LES and acoustic requirements were fulfilled, leading to a mesh of 380 million cells. The simulation was performed during five revolutions and statistical convergence was reached. Inspections of the flow-fields highlight a consistent behaviour of the shielding function (border between RANS and LES solving areas) around the blade walls, at the trailing-edge and in the tip gap flow areas. Comparisons with performance and hot-wire measurements are also presented. Aerodynamic performance and radial evolution of averaged velocities on a plane in-between the fan and the OGV are well retrieved, both in shape and levels. For the turbulent quantities, the shape of the radial profiles are close to the measurements, with much better accuracy in the upper region compared to the RANS solution.

scholarly journals Numerical Modelization of the Flow in Centrifugal Pump: Volute Influence in Velocity and Pressure Fields

2005 ◽  
Vol 2005 (3) ◽  
pp. 244-255 ◽  
Author(s):  
Miguel Asuaje ◽  
Farid Bakir ◽  
Smaïne Kouidri ◽  
Frank Kenyery ◽  
Robert Rey
Keyword(s):  
Centrifugal Pump ◽  
Cfd Simulation ◽  
Pressure Field ◽  
Flow Simulation ◽  
Turbulence Models ◽  
3D Flow ◽  
Structured Grid ◽  
Pressure Fields ◽  
Pump Shaft ◽  
Radial Thrust

A 3D-CFD simulation of the impeller and volute of a centrifugal pump has been performed using CFX codes. The pump has a specific speed of 32 (metric units) and an outside impeller diameter of 400 mm. First, a 3D flow simulation for the impeller with a structured grid is presented. A sensitivity analysis regarding grid quality and turbulence models were also performed. The final impeller model obtained was used for a 3D quasi-unsteady flow simulation of the impeller-volute stage. A procedure for designing the volute, the nonstructured grid generation in the volute, and the interface flow passage between the impeller and volute are discussed. This flow simulation was carried out for several impeller blades and volute tongue relative positions. As a result, velocity and pressure field were calculated for different flow rates, allowing to obtain the radial thrust on the pump shaft.

Study of Unsteady Vortical Structures in Axisymmetric Hydrodynamic Chamber

2013 ◽  
Vol 8 (4) ◽  
pp. 76-83
Author(s):  
Alexey Vinokurov ◽  
Sergey Shtork ◽  
Sergey Alekseenko
Keyword(s):  
Fluid Dynamic ◽  
Numerical Data ◽  
Detached Eddy Simulation ◽  
Isothermal Model ◽  
Pressure Drops ◽  
Vortical Structures ◽  
Eddy Simulation ◽  
Precessing Vortex Core ◽  
Axisymmetric Vortex ◽  
Vortex Burner

The paper is devoted to experimental and numerical investigation of unsteady vortical processes in the isothermal model of axisymmetric vortex burner. Obtained characteristics of precessing vortex core (PVC) show the dependences of PVC`s frequency on flowrate, swirl number and nozzle`s diameter. Pressure drops inside the chamber also have been measured. Laser Doppler Anemometer (LDA) has been used to explore spatial distribution of mean axial velocity. Numerical simulation has been carried out by using computational fluid dynamic (CFD) program Adapco Star-CCM+. Detached Eddy Simulation approach and Spalart-Allmaras model have been used for calculating the flow. Results of comparison of experimental and numerical data have shown validity of used numerical method. Combination of experimental and mathematical modeling gives the possibility of obtaining detailed information representing comprehensive description of spatially complex unsteady flow with the PVC

Unit-Tests Based Validation and Verification of Numerical Procedure to Predict Vortex-Induced Motion

2006 ◽  
Author(s):  
David Schowalter ◽  
Indradeep Ghosh ◽  
Sung-Eun Kim ◽  
Ahmad Haidari
Keyword(s):  
Degrees Of Freedom ◽  
Hybrid Approach ◽  
Numerical Procedure ◽  
Reynolds Numbers ◽  
Physical Models ◽  
Navier Stokes ◽  
Detached Eddy Simulation ◽  
Validation And Verification ◽  
Eddy Simulation ◽  
Induced Motion

Vortex-induced vibration of a circular cylinder with two degrees-of-freedom (2-DOF) is numerically studied using a mixed Lagrangian-Eulerian approach at several Reynolds numbers. The computations were carried out using a parallelized finite-volume Navier-Stokes solver based on a multidimensional linear reconstruction scheme that allows use of unstructured meshes. The effects of turbulence are modeled using an approach based on unsteady Reynolds-averaged Navier-Stokes (URANS) equations and a hybrid approach often referred to as detached eddy simulation (DES). In order to better understand the potential sources of the prediction error, a systematic verification and validation of the numerics and the physical models is attempted in this study with problems of progressively increasing complexity.

Prediction of Aeroacoustic and Control over a Cavity by Delayed Detached Eddy Simulation

2014 ◽  
Vol 598 ◽  
pp. 505-509 ◽  
Author(s):  
Yu Liu ◽  
Ming Bo Tong
Keyword(s):  
Sound Pressure ◽  
Noise Suppression ◽  
Cfd Simulation ◽  
Leading Edge ◽  
Pressure Level ◽  
Detached Eddy Simulation ◽  
Suppression Effect ◽  
Eddy Simulation ◽  
Delayed Detached Eddy Simulation ◽  
And Control

In the present study CFD simulation with delayed detached eddy simulation (DDES) are performed to investigate an open cavity at Mach 0.85. Two cavity configurations, clean cavity and cavity with a leading-edge saw tooth spoiler, are modeled. The results obtained from clean cavity prediction are compared with experimental sound pressure level (SPL) data from QinetiQ, UK. Furthermore, comparisons are made with the predicted SPL between the two configurations. The main focuses of this investigation are to obtain a further understanding of the cavity aeroacoustics and test the noise suppression effect by a saw tooth spoiler.

scholarly journals CFD Simulation and Mitigation with Boiling Liquid Expanding Vapor Explosion (BLEVE) Caused by Jet Fire

2018 ◽  
Vol 3 (1) ◽  
pp. 1 ◽  
Author(s):  
Alon Davidy
Keyword(s):  
Cfd Simulation ◽  
Fluid Dynamic ◽  
Heat Fluxes ◽  
Heat Transfer Analysis ◽  
Superheated Liquid ◽  
Vapor Explosion ◽  
Fire Dynamics ◽  
Boiling Liquid ◽  
Eddy Simulation ◽  
The People

Different kinds of explosions are driven by the internal energy accumulated in compressed gas or superheated liquid. A well-known example of such an explosion is the burst of a vessel with pressure-liquefied substance, known as Boiling Liquid Expanding Vapor Explosion (BLEVE). Hot BLEVE accident is caused mainly by direct heating (pool fire or jet fire) of the steel casing at the vapor side of the tank to temperatures in excess of 400 °C. Thermal insulation around the tank can significantly reduce and retard the excessive heating of the tank casings in a fire. This will allow fire fighters enough time to reach the accident location and to cool the LPG (Liquid Petroleum Gas) tank to avoid the BLEVE, to extinguish the fire or to evacuate the people in the vicinity of the accident. The proposed algorithm addresses several aspects of the BLEVE accident and its mitigation: Computational Fluid Dynamic (CFD) Simulation of jet fire by using fire dynamics simulator (FDS) software by using large eddy simulation (LES); calculation of the convective and radiative heat fluxes by using the impinging jet fire theory; performing thermochemical and heat transfer analysis on the glass-woven vinyl ester coating of the vessel by using FDS software (version 5); and COMSOL Multiphysics (version 4.3b) during the heating phase of composite and calculation of the time period required to evaporate the liquefied propane by using the first and second laws of thermodynamics.

scholarly journals CFD Simulation of Air Flow Over an Object with Gable Roof, Revised with Y+ Approach

2016 ◽  
Vol 16 (2) ◽  
pp. 85-94
Author(s):  
Juraj Králik
Keyword(s):  
Cfd Simulation ◽  
Turbulence Models ◽  
External Pressure ◽  
Dynamics Simulation ◽  
Detached Eddy Simulation ◽  
Eddy Simulation ◽  
Fine Mesh ◽  
Gable Roof ◽  
Computer Fluid Dynamics ◽  
Polyhedral Mesh

Abstract Aim of this contribution is to provide insight view into analysis focused on obtaining external pressure coefficients on isolated two storey low-rise building with 15° elevation gable roof using Computer Fluid Dynamics simulation and these are compared to values that offering Eurocodes. Final Volume Model consisting of polyhedral mesh will be used for analysis with two different turbulence models. Mesh was created with respect to y+ parameter, where desired value was below one which leads us to fine mesh type. Secondary aim of this contribution is to compare performance of selected turbulence models. For this purpose were chosen Detached Eddy Simulation and Large Eddy Simulation which are part of the Scale Resolving Simulation turbulence models.

CFD Simulation of a Twin-Screw Ship Self-Propulsion Using DDES-Overset Method

2019 ◽  
Author(s):  
Jianhua Wang ◽  
Decheng Wan
Keyword(s):  
Cfd Simulation ◽  
Ship Hull ◽  
The Self ◽  
Detached Eddy Simulation ◽  
Complex Flow ◽  
Ship Model ◽  
Eddy Simulation ◽  
Delayed Detached Eddy Simulation ◽  
Twin Screw ◽  
Cfd Method

Abstract Rotating propellers and moving rudders are necessary for the simulation of free running ship with the purpose of resolving detailed flow interaction. In the present work, CFD method is used to numerically investigate self-propulsion behavior for a twin-screw fully appended ship. The simulation conditions are following the experiment performed at IIHR. The benchmark ship model ONR Tumblehome is used for all the numerical computations. Overset grids are used to fully discretize the ship hull, twin propellers and rudders. Self-propulsion simulation is carried out using a PI controller to achieve target ship speed of Fr = 0.20 in calm water and the ship model is free to trim and sinkage. All the numerical calculations are carried out by the in-house CFD solver naoe-FOAM-SJTU. Unlike most previous studies based on RANS method, the present self-propulsion simulations adopt the Delayed Detached-Eddy-Simulation (DDES) approach to resolve the complex flow around ship hull, propeller and rudder. The main parameters of the self-propulsion as well as flow visualizations are presented. The predicted results are compared with previous RANS data and the available experimental data. The comparison with the experiment is satisfactory and the flow field shows that the present DDES-overset method can give more flow details for the self-propulsion condition.

scholarly journals Aeroacoustic Investigation of Passive and Active Control on Cavity Flowfields Using Delayed Detached Eddy Simulation

2019 ◽  
Vol 2019 ◽  
pp. 1-9
Author(s):  
Yu Liu ◽  
Yong Shi ◽  
Mingbo Tong ◽  
Fei Zhao ◽  
Binqi Chen
Keyword(s):  
Active Control ◽  
Sound Pressure Level ◽  
Sound Pressure ◽  
Passive Control ◽  
Cfd Simulation ◽  
Pressure Level ◽  
Control Methods ◽  
Detached Eddy Simulation ◽  
Eddy Simulation ◽  
Delayed Detached Eddy Simulation

In the present study, CFD simulation with delayed detached eddy simulation (DDES) is performed to investigate an open cavity at Mach 0.85. A clean cavity and cavity with passive and active control methods, including sawtooth spoiler, flat-top spoiler, crossflow rod, and steady leading edge blowing, are analyzed. The results obtained from all the control methods are compared with clean cavity, and all the flow control methods show positive effect on the overall sound pressure level reduction with the decrement up to 8 dB. The effect of active control on sound pressure level in the cavity is much better than that of passive control, with the magnitude of tone noise decreasing by 20-30 dB. The main focus of this investigation is to test the noise suppression effect by passive and active control methods.

Numerical Study of NACA 0012 Aeroacoustics Response for Normal and Icing Conditions

2018 ◽  
Vol 875 ◽  
pp. 89-93
Author(s):  
Edison H. Caicedo ◽  
Muhammad S. Virk
Keyword(s):  
Numerical Study ◽  
Turbulence Models ◽  
Aerodynamic Characteristics ◽  
Sound Level ◽  
Detached Eddy Simulation ◽  
Blade Profile ◽  
Eddy Simulation ◽  
Naca0012 Airfoil ◽  
Layer Flow ◽  
Naca 0012

This paper describes a multiphase computational fluid dynamics (CFD) based numerical study about aeroacoustics response of NACA0012 airfoil for both normal and icing conditions. Three different turbulence models (RANS, DES & LES) are tested where Detached Eddy simulation (DES) turbulence modelling approach is found suitable for this case study. Aeroacoustics numerical results for clean NACA 0012 are compared with the experimental data obtained from NASA report 1218 [1], where a good agreement is found. An extended CFD study is carried out for iced NACA 0012 airfoil, where results show more boundary layer flow separation in case of iced blade profile that leads to a change in the aerodynamic characteristics of the blade profile and increase in sound level for iced airfoil as compared to the clean NACA0012 airfoil.

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