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Lestriez R.,NumIberica | Amet E.,NUMECA International | Tartinville B.,NUMECA International | Hirsch C.,NUMECA International
IOP Conference Series: Earth and Environmental Science | Year: 2016

This work investigates the use of the non-linear harmonic (NLH) method for a high- head Francis turbine, the Francis99 workshop test case. The NLH method relies on a Fourier decomposition of the unsteady flow components in harmonics of Blade Passing Frequencies (BPF), which are the fundamentals of the periodic disturbances generated by the adjacent blade rows. The unsteady flow solution is obtained by marching in pseudo-time to a steady-state solution of the transport equations associated with the time-mean, the BPFs and their harmonics. Thanks to this transposition into frequency domain, meshing only one blade channel is sufficient, like for a steady flow simulation. Notable benefits in terms of computing costs and engineering time can therefore be obtained compared to classical time marching approach using sliding grid techniques. The method has been applied for three operating points of the Francis99 workshop high-head Francis turbine. Steady and NLH flow simulations have been carried out for these configurations. Impact of the grid size and near-wall refinement is analysed on all operating points for steady simulations and for Best Efficiency Point (BEP) for NLH simulations. Then, NLH results for a selected grid size are compared for the three different operating points, reproducing the tendencies observed in the experiment. © Published under licence by IOP Publishing Ltd.

Sarasota, FL, Dec. 23, 2016 (GLOBE NEWSWIRE) -- Zion Market Research has published a new report titled “Computer Aided Engineering Market (Finite Element Analysis and Computational Fluid Dynamics) for Aerospace, Automobile, Electronic and Electricals Defense, Industrial Machineries and Other Applications: Global Industry Perspective, Comprehensive Analysis and Forecast, 2015-2021”. According to the report, global demand for computer aided engineering market was valued at around USD 3,062.37 billion in 2015 and is expected to reach approximately USD 5,863.36 million in 2021, growing at a CAGR of slightly above 11.10% between 2016 and 2021. Computer aided engineering (CAE) aids in solving engineering problems through the use of sophisticated and interactive graphical software. CAE is software used to design, analyze, and manufacture products and processes. Browse through 13 Market Tables and 21 Figures spread over 110 Pages and in-depth TOC on “Global Computer Aided Engineering (CAE) Market: By Product, Size, Share, Trends, Industry Segments and Forecast, 2015 – 2021”. Growing trend of smartphones and tablets are expected to boost the growth of this market. Rising use of new engineering modes such as building information modeling, 3D printing, 3D modeling, and concurrent engineering are major drivers for the computer aided engineering software market. However, increasing the threat of open-source and piracy of CAE software could negatively impact the computer aided engineering market growth. Lack of technical expertise and skilled labor is expected to hamper market growth over the forecast period. Nonetheless, Cloud-based computer aided engineering tools may help market vendors to increase market penetration in small and medium sectors by offering benefits such as low operating and maintenance costs and mobility for the companies. Computer aided engineering is the vital part of many global industries for economic growth including automotive, oil, aerospace, defense, finance and healthcare etc. Browse the full "Computer Aided Engineering Market (Finite Element Analysis and Computational Fluid Dynamics) for Aerospace, Automobile, Electronic and Electricals Defense, Industrial Machineries and Other Applications: Global Industry Perspective, Comprehensive Analysis and Forecast, 2015-2021" report at In terms of revenue, North America held the largest share of global computer aided detection market and is expected to dominate the market over the next few years. This growth is mainly due to advancement in technology and adoption of new trends in image analysis and pattern recognition algorithm to workflow management functions for the diseases and conditions. The U.S. held the most significant market for computer aided detection as it is a key innovation hub and leading companies in the segment have been conducting thorough R&D. In 2015, North America was followed by Europe in terms of revenue. Europe was the second largest regional market increasing chronic diseases. Moreover, the adoption of new technologies is expected to witness significant growth in the years to come. The growth in the market is led by rising awareness for health and rapid expansion of the healthcare industry. Inquire more about this report @ Asia Pacific is expected to be the fastest growing market in near future. This growth is mainly due to rise cost-effective technologies, demand for medical tourism, and government initiatives. Asia Pacific computer aided detection market is mainly driven by the increasing population, rising incidence rate of chronic diseases, coupled with the rising health awareness among people, especially in China and India. The Middle East & Africa regional market is expected to witness moderate growth in the near future. The growth is attributed to rapid growth in aging population coupled with health care awareness regarding the chronic disease. Latin America is another important regional market and is expected to experience significant growth over the forecast period. Increasing healthcare industry coupled with the adoption of new technology developed for computer aided detection in Brazil is anticipated to fuel market growth in Latin America. Major players in the CAE market include   S.A., and Synopsys, Inc., ,Bentley Systems,PLM Software, Inc., Mentor Graphics Corporation, Exa Corporation, MSC Software Corporation,  Inc., NEi Software, Dassault Systemes, ANSYS Inc., and AspenTech, ESI Group,  and Numeca International, among others. The report segment of global computer aided engineering market as follows: Global Computer Aided Engineering: Product Segment Analysis Zion Market Research is an obligated company. We create futuristic, cutting edge, informative reports ranging from industry reports, the company reports to country reports. We provide our clients not only with market statistics unveiled by avowed private publishers and public organizations but also with vogue and newest industry reports along with pre-eminent and niche company profiles. Our database of market research reports comprises a wide variety of reports from cardinal industries. Our database is been updated constantly in order to fulfill our clients with prompt and direct online access to our database. Keeping in mind the client’s needs, we have included expert insights on global industries, products, and market trends in this database. Last but not the least, we make it our duty to ensure the success of clients connected to us—after all—if you do well, a little of the light shines on us.

Di Francescantonio P.,Scientific and Technical Software | Hirsch C.,NUMECA International | Ferrante P.,NUMECA International | Isono K.,NUMECA Japan
SAE Technical Papers | Year: 2015

A new method called Adaptive Spectral Reconstruction (ASR) for the stochastic reconstruction of broadband aeroacoustic sources starting from steady CFD analyses is presented and applied to the evaluation of the noise radiated by a model automotive side mirror. The new approach exploits some ideas from both SNGR and RPM, and for some aspects can be considered as a sort of mixing between the two methods since it permits to reconstruct both the frequency content of the turbulent field (as done by SNGR) and the spatial cross correlation (as done by RPM). The turbulent field is reconstructed with a sum of convected plane waves, but two substantial differences are introduced in respect of SNGR. The first difference concerns the spatial variation of the parameters that define each wave, that depends on the wavelength of each wave, rather than being kept constant or related to the CFD correlation length. The second innovative aspect is the usage of a dedicated full hexa adaptive mesh that is refined in function of the expected local correlation length, ensuring that the mesh be enough refined to capture the relevant acoustic length scales. The method is here applied to the evaluation of a classical side mirror model test case, and results are presented in terms of comparisons with measurements for both in plane and out of plane microphones. Visualizations of reconstructed acoustic sources are also presented. Copyright © 2015 SAE International.

Bruce P.J.K.,University of Cambridge | Bruce P.J.K.,Imperial College London | Babinsky H.,University of Cambridge | Tartinville B.,NUMECA International | And 2 more authors.
AIAA Journal | Year: 2011

An experimental and numerical investigation into transonic shock/boundary-layer interactions in rectangular ducts has been performed. Experiments have shown that flow development in the corners of transonic shock/boundary-layer interactions in confined channels can have a significant impact on the entire flowfield. As shock strength is increased from M∞ = 1:3 to 1.5, the flowfield becomes very slightly asymmetrical. The interaction of corner flows with one another is thought to be a potential cause of this asymmetry. Thus, factors that govern the size of corner interactions (such as interaction strength) and their proximity to one another (such as tunnel aspect ratio) can affect flow symmetry. The results of the computational study show reasonable agreement with experiments, although simulations with particular turbulence models predict highly asymmetrical solutions for flows that were predominantly symmetrical in experiments. These discrepancies are attributed to the tendency of numerical schemes to overprediction corner-interaction size, and this also accounts for why computational fluid dynamics predicts the onset of asymmetry at lower shock strengths than in experiments. The findings of this study highlight the importance of making informed decisions about imposing artificial constraints on symmetry and boundary conditions for internal transonic flows. Future effort into modeling corner flows accurately is required. Copyright © 2011 by the American Institute of Aeronautics and Astronautics, Inc. All rights reserved.

Marlier J.,CRYOSTAR France | Barbieux V.,NUMFLO | Tartinville B.,NUMECA International
Proceedings of the ASME Turbo Expo | Year: 2016

Radial inflow turbines with pivoting stator vanes are known to keep a high level of efficiency over a large flow range. This turbine type maintains a good efficiency level at reduced speed because the turbine wheel is not very sensitive to negative incidence. For these reasons variable geometry radial inflow turbines are used where a large operating map is required. However, it is known from literature that impeller blades undergo significant unsteady aerodynamic forces due to upstream stator vanes, especially with transonic conditions at stator exit, which are quite common for these machines. From a mechanical point of view, the number of stator vanes is therefore crucial since it determines the excitation frequency. Over a large operating map, it is not possible to avoid all eigenmodes. The vane count shall avoid excitation of impeller critical eigenmodes, especially if their mode shape matches. Amongst unsteady phenomena occurring in turbomachinery, rotor/stator interactions are of primary importance. Independently from impeller eigenmodes, this study discusses the unsteady rotating radial load on the impeller that can be generated under specific blade count combinations, for a single stage radial inflow turbine. This radial load can indeed be large and impact the rotordynamics. The rotating frequency of the load is given by Tyler-Sofrin theory. In order to compute its amplitude, unsteady CFD is performed, with the use of the non-linear harmonic method implemented into FINE™/Turbo software from NUMECA. The effects of the fluid, of the operating conditions and of the rotational speed are also quantified. Under specific conditions, resonance may occur and is discussed. Copyright © 2016 by ASME.

di Francescantonio P.,STS Inc | Ferrante P.,NUMECA International | Deconinck T.,NUMECA International | Hirsch C.,NUMECA International
19th AIAA/CEAS Aeroacoustics Conference | Year: 2013

The application of synthetic turbulence reconstruction models for flow noise prediction is quite attractive from an industrial point of view due to the limited resource required, but up to now it has not been widely adopted due to a lack of confidence in the results that could be obtained. The SNGR method is therefore analyzed performing some convergence tests that shows how the main source of problems seems to be related to the lack of converge when the maximum wavenumber is increased. A physical reason for this lack of convergence is identified in the fact that the SNGR method does not model the continuous energy transfer typical of turbulence cascade and this is particular relevant for sound radiation since the energy transfer process greatly reduces the time correlation of turbulent structures. A modified formulation called DSNG (Damped Stochastic Noise generation) is introduced to solve this problem, and is implemented in the Fine/Acoustic code. Convergence tests are presented that show how the new formulation permits to obtain fully converged results where the standard SNGR method diverge, and good comparison with experimental results are presented for a jet noise test case and for an airfoil plus slat configuration.

Horcas S.G.,University of Mons | Debrabandere F.,NUMECA International | Tartinville B.,NUMECA International | Hirsch C.,NUMECA International | Coussement G.,University of Mons
Wind Energy | Year: 2016

In this paper, a computational study of the DTU 10MW reference wind turbine unsteady aerodynamics is presented. The whole wind turbine assembly was considered, including the complete rotor and the tower. The FINE/Turbo flow solver developed by NUMECA International was employed for the simulations. In particular, the Non-Linear Harmonic (NLH) method was applied in order to accurately model flow unsteadiness at reduced computational cost. Important vortex shedding structures were identified at low blade span range and all along the tower height. A strong interaction between rotor and tower flows was also observed. Lastly, the performance of the NLH approach was compared against a standard Unsteady Reynolds-Averaged Navier Stokes simulation. The same complex unsteady flow phenomena were captured by both technologies. Nevertheless, the NLH approach was found to be 10 times faster than the Unsteady Reynolds-Averaged Navier Stokes method for this particular application. © 2016 John Wiley & Sons, Ltd.

Vilmin S.,Numeca International | Lorrain E.,Numeca International | Tartinville B.,Numeca International | Capron A.,Numeca International | Hirsch C.,Numeca International
International Journal of Computational Fluid Dynamics | Year: 2013

The nonlinear harmonic method (NLH) and its extension to the modelling of the clocking effects can simulate the unsteady flows in multistage machines at much lower CPU cost. The bladerow interactions that can be reproduced are those between adjacent rotors and stators and also between successive rotors or successive stators, including the contra-rotating open rotors (CROR). However, the simulation of the unsteady effects of the engine pylon on the flow in the rear rotor requires the modelling of the time-varying disturbance from a stator of periodicity 1 (the pylon) into a rotor that is not adjacent, requiring an extension of the current NLH method. In addition, it has been observed that in some stator1/rotor/stator2 configurations, the amplitude of the perturbation associated with a blade passing frequency (BPF) in a row is not only created by the adjacent row but is also modified in space by the interaction of the periodic disturbances coming from the other two rows. For instance, for a struts/rotor/stator machine, the spatial frequencies of the periodic disturbance in the stator could be provoked not only by the interaction with the adjacent rotor but also by an additional interaction with the periodic flow coming from the struts. The present paper introduces a method that enables the identification of these spatial frequencies for a general row1/row2/row3 configuration. Besides, any row can be a stator or a rotor and the time-varying disturbances are not only produced by the interaction with the adjacent row but also with the other rows. A more general NLH method is therefore obtained. The proposed method was validated against a three-cylinder test case, a CROR test case, a struts/rotor/stator case and an impeller/bladed diffuser/volute case. © 2013 Copyright Taylor and Francis Group, LLC.

Tartinville B.,NUMECA International | Hirsch C.,NUMECA International
Proceedings of the ASME Turbo Expo | Year: 2015

The objective of this paper is to numerically investigate the unsteadineß generated by a bladed diffuser on an upstream centrifugal impeller. The Non-Linear Harmonic (NLH for short) time-spectral method has been retained here. The major advantage of such a method is that it requires much leß computational effort than a standard unsteady simulation. In order to further reduce the computing time, the NLH method has been extended to low speed flows by using a preconditioning technic. Therefore, the NLH method can be accurately applied to any Mach number flow and even to purely incompreßible fluids. This extension of the flow solver has been validated on a wide range of simple test cases at various reduce frequencies. Solutions have been compared to purely unsteady approach and also to experimental data. In a second step, the NLH method has been applied to a centrifugal impeller and its downstream diffuser. Numerical results have been analyzed and compared to the available experimental data showing the significant influence of the downstream diffuser on the impeller preßure load. Copyright © 2015 by ASME.

Hirsch C.,NUMECA International
28th AIAA Applied Aerodynamics Conference | Year: 2010

Two representative test cases of shock wave boundary layer interactions (SWBLI) were simulated by a large number of groups, with models including RANS and LES models. The paper will review the main trends of the presented results, identifying strengths and weaknesses of turbulence models, in view of the three-dimensionality of the flow and the extend of the separation region. Trends of the CFD results are discussed and recommendations for future actions are suggested. © 2010 by Charles Hirsch.

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