Experimental and Computational Study of Unsteady Flow and Noise in a Lawnmower Casing

In order to supply tools for low noise design to the manufacturers of lawnmowers CETIM has set up a research project on blade noise (which is predominant on medium size and big machines). Experimental studies are based on the use of a special test rig which allows to measure blade noise without disturbances from the drive unit and to determine simultaneously the pressure fluctuations generated by the blade.

 

Numerical simulations using CFD software allow computation of the unsteady pressure field distribution inside the casing, identification of pseudosound perturbations near the blade and localisation of flow recirculation areas near to the casing outlet.

M.Bockhoffa, K.Monesa, Centre Technique des Industries Mécaniques (CETIM), France

S.Timouchevb K.Ilhichov, InteRe Co Ltd, Khimki, Russia

A.Aksenov, TESIS, Moscow, Russia

Download PDF, 0.38 MB


Drop-test FSI Simulation with Abaqus and FlowVision Based on the Direct 2-Way Coupling Approach

The paper presents a numerical simulation of the drop test in a still water for the multi-component box structure. The complexity of the problem is in the strong fluid-structure interaction (FSI) between the box and the water free surface. The numerical simulation of the drop test is performed with two software tools: Abaqus and FlowVision through the direct coupling interface, which manipulates, on the Abaqus side the Lagrangian finite-element mesh and on the FlowVision side the Eulerian finite-volume mesh with subgrid geometry resolution.

The novel approach is that there are no auxilliary structure models (or 3rd party software) integrated in the applied software solution: the finite-element mesh is defined from the Cartesian CFD finite-volume mesh and all the relationships between the CFD mesh cells and the outside FE faces are fully preserved. Each mesh node displacement is directly transferred between FlowVision and Abaqus, thus avoiding any additional interpolation.

A. Aksenov, D.Korenev, A. Shyshaeva, TESIS Ltd, Russia

D. Vucinic, Vrije Universiteite Brussel, Belgium

Z. Mravak, Bureau VERITAS, France

2008 ABAQUS Users’ Conference, Page 1/15

Download PDF, 1.32 MB


Coupled CFD and Structural Analysis for World Outright Sailing Speed Record Preparations

The brief for the boat, v-39 Albatross is to set a new world outright sailing speed record at Portland Harbor, UK by 2013. The boat is configured to add at least 10 knots to the current record by setting a speed above 65 knots (120 km/h). At speed the boat hulls will fly above the surface using a wing in ground effect. The pilot is able to sail on both port and starboard tack and can actively control the craft in speed, roll and height as well as direction.

Verney Yachts and Capvidia are carrying out transient Fluid Structure Interaction (FSI) simulations using Abaqus/Standard coupled with FlowVision-HPC from Capvidia. The objectives of the simulations described in this paper are to capture the above surface aerodynamics of the boat, and to establish overall aerodynamic forces and moments acting on the boat with different control inputs and boat speeds. Each FSI analysis involves capturing the movement of six independently rotating surfaces (four wing-sail surfaces and two outriggers), each surface able to freely weathervane into the local airflow. This process allows the control system to be tuned to minimize control cross coupling and to maximize forward thrust, whilst maintaining roll balance of the overall boat.
The work presented herein is being carried out alongside Computational Fluid Dynamics (CFD) analyses of the free surface hydrodynamics. The data generated will be pulled together into a final series of mathematical models to plot and analyze the forces and moments acting on the boat as the speed increases, mapping the way the boat will behave.

T Clarke and S Howell, Verney Yachts, UK

Andrey Aksenov, Igor Moskalev, Konstantin Kuznetsov, CAPVIDIA, Russia

2011 SIMULIA Customer Conference, Page 1/17

Download PDF, 0.56 MB


Computational Study of Pressure Pulsation in a Medium Specific Speed Pump

The centrifugal pump of high specific speed with a diagonal type of impeller flow is studied experimentally and numerically. 2D and 3D numerical methods are used with applying acoustics – vortex equations.

Increasing energetic parameters of centrifugal pumps requires a more complex geometry of the impeller and volute as one need to raise the specific speed of the pump to provide a higher efficiency value. The pump of higher specific speed has an impeller with curved blades and diagonal meridional section. The flow outgoing the impeller has an essential axial component of velocity. Thus the two dimensional approach will not give the accurate prediction of pressure pulsations in the volute casing. This is why the new 3-dimensional method has been elaborated for this task. The 3D computational results of pressure pulsation are compared with those obtained by 2D computation Measurements show that in the beginning of volute, in the pseudo-sound zone, amplitude of Blade Passing Frequency (BPF) spectral component is higher than that at the pump outlet by an order of magnitude. 3-Dimensional analysis gives a good agreement with experimental data while 2D prediction underestimates the BPF amplitude in the beginning of volute.

Serguei Timouchev, InteRe Ltd

Andrey Aksenov, Tesis Ltd

Proceedings of FEDSM2005: 2005 ASME Fluids Engineering Division Summer Meeting and Exhibition, Page 1/9

Download PDF, 0.4 MB


Computational Study of Ejector-Pumps

Computational results of 3D turbulent compressible gas flow in a single-nozzle ejector are compared with experimental data. Full Navier-Stokes equations and k- model of turbulence are used for mathematical model of gas flow. In computations the suction gas flow rate was determined and compared with experimental one. Two computational grids – coarse and fine are used to perform simulation.

The fine grid is differ from coarse one by adaptation near the nozzle of active gas.Comparison of results carried out on coarse and fine grids shows that the accuracy of coarse grid is enough to get reliable results. Difference of computed and experimental results is less then 4% for the flow rate of passive gas.These results enable to make

These results enable to make computational study of the multi-nozzle water-steam ejector. Condensation of steam is taken into account by introducing the equilibrium model of condensation. It is found that location of nozzles and its length are the important parameters of ejector influencing considerably its characteristics.

Serguei Timouchev, InteRe Ltd

Andrey Aksenov, Tesis Ltd

Victor Bogdanov, MSIU

Proceedings of FEDSM2005: 2005 ASME Fluids Engineering Division Summer Meeting and Exhibition, Page 1/6

Download PDF, 0.57 MB


Computation of Perspective KRISO Containership Towing Tests with the Help of the Complex of Hydrodynamical Analysis in FlowVision

Computation of the ship hull flow with the help of complexes of hydrodynamical analysis now gets the increasing practical value in the domestic and foreign design organizations.

The report is devoted to a series of calculations of perspective containership towing resistance, executed in a program complex FlowVision. The ship developed in the Korea Researche Institu for Ships and Ocean Engineering (KRISO).

Andrew V. Pechenyuk, Digital Marine Technology

Download PDF, 0.64 MB


CFD Study of Prospective 1st Stage Centrifugal Impeller Design

CFD analysis of two first – stage centrifugal impellers is undertaken with the main goal to obtain additional evaluation data regarding flow characteristics of the old first stage impeller design and in the proposed new cantilever impeller design.

The new design is developed to reduce the 1st stage impeller cavitation erosion damage of a multistage centrifugal feed pump. This stage of work comprises computational tests of both impeller models under the same mode of operation, 3000 RPM and volumetric flow rate 0.0503 m3/s. Both impellers are planning to be tested experimentally. The inlet geometry for CFD tests is taken from the test facility draft. The outlet is made like a circular vaneless diffuser. In the old design, a hub developed upstream presents the through shaft. Computational results are compared with the head/efficiency data delivered by plane cascade theory. Computational data shows an advantage of the new design by head and efficiency although the efficiency level is underestimated. Computational data shows lower pressure zones in the proposed design are localized at the impeller inlet periphery, in the old design lower pressure zones spreads along the blade inlet height. Further computational test will be made for the whole geometry including the stage stator part and experimental validation of the proposed design will follow.

Sergey S. Panaiotti, Moscow Bauman State Technical University

Upendra Singh Rohatgi, Brookhaven National Lab

Sergey F. Timuchev, Moscow Aviation Institute

Vladimir A. Soldatov, Russian Research Center “Kurchatov Institute”

Boris N. Chumachenko, Keldysh Research Center

Proceedings of FEDSM2007, 5th Joint ASME/JSME Fluids Engineering Conference, Page 1/6

Download PDF, 0.47 MB


Aerodynamic of Reentry Spacecraft Clipper

At present time RSC Energia is carrying out research work on designing the reentry manned spacecraft of new generation to crew deliver, in-flight support and return. The spacecraft ought to take the place of Soyuz. Manned spacecraft Clipper having the reentry vehicle (RV) of lifting body type is a possible alternate solution (Fig. 1). In comparison with Soyuz suggested RV provides higher maneuverability and less overloading during descent phase.

Experimental and numerical investigations of reentry vehicle aerodynamic characteristics at descent phase have been carried out. The main peculiar properties of flowing about spacecraft have been revealed. Possibility of using Russia software for investigations of aerodynamics of lifting body type vehicles at a design phase is shown. Comparison of experimental and numerical results is presented.

A.A. Dyadkin, A.N. Krylov, A.G. Reshetin, Yu.P. Semenov, T.V. Simakova, V.A. Tokarev
S.P. Korolev Rocket and Space Corporation Energia, Korolev, Russia
M.N. Kazakov
Central Research and Development Institute of Mechanical Engineering, (TSNIIMASH), Korolev, Russia

EUROPEAN CONFERENCE FOR AEROSPACE SCIENCES (EUCASS), Page 1/7

Download PDF, 0.48 MB


Overcoming of Barrier Between CAD and CFD by Modified Finite Volume Method

An advanced finite-volume method (method of modified finite volumes) for numerical simulation of flows in industrial applications and its implementation in code FlowVision is proposed. The method is based on non-staggered Cartesian grid with adaptive local refinement and a subgrid geometry resolution method for description of curvilinear complex boundaries. Semi-Lagrange approach for solution of convective transport equation and splitting algorithm for solution of Navier-Stokes equations are presented.

Opportunity of solution of real industrial problems by the method of modified finite volumes is estimated. Geometry of computational domain is specified by CAD system and is imported by FlowVision through VRML or STL file. Two different problems was investigated by the proposed method. The first problem is an aquaplane of car tire on road with water layer, the second — a combustion of methane in air by low NOx burner of power station boiler.

A. Aksenov, A. Dyadkin, V. Pokhilko, TESIS, Russia

Download PDF, 0.5 MB


Onset of Leviation in Thrust Bearing; FSI Study using Abaqus-FlowVision Coupling

Lift force formation in a thrust bearing of 800-tons rotor of electric power station is discussed in the given paper. The problem is solved numerically. Direct coupling between finite-element system Abaqus calculating stress and strain state of an bearing parts and finite-volume system FlowVision-HPC calculating oil flow in gap between a collar and a shoe of bearing is used. The shape of the gap between the shoe and the collar, the clearance value, the moment of the friction force, and the temperature distribution of oil over the clearance are determined.

 

Ricky Chen, Taiwan Power Company, Taiwan

A. Aksenov, A. Shishaeva, TESIS Ltd, Russia/CAPVIDIA, Belgium,

Frank Kuo, Samwell Company, Taiwan

SIMULIA Customer Conference 2010, Page1/9

Download PDF, 0.86 MB


Numerical Simulation of Car Tire Aquaplaning

Approach to numerical simulation of water and air flow around aquaplaning car tire is described. The approach for governing equations solving is based on a finite-volume method and non-staggered Cartesian adaptive locally refined grid. A method of subgrid geometry resolution is proposed for accurate description of curvilinear complex boundaries. This method uses a presentation of boundaries as a set of plane facets and makes CFD code compatible with CAD systems. The described technology is implemented in FlowVision code. Some results of simulation of car tire aquaplaning performed by FlowVision are presented The tire lift dependence on a tread picture is calculated.

 

A. Aksenov, A. Dyadkin, A. Gudzovsky

ECCOMAS 96.
Published in 1996 by John Wiley & Sons, Ltd.

Download PDF, 0.27 MB


1 2 4