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103 results on '"CAMPOBASSO M"'

9. Optimised hybrid parallelisation of a CFD code on Many Core architectures

Author

Jackson, Adrian and Campobasso, M. Sergio

Subjects
Computer Science - Distributed, Parallel, and Cluster Computing
Abstract

COSA is a novel CFD system based on the compressible Navier-Stokes model for unsteady aerodynamics and aeroelasticity of fixed structures, rotary wings and turbomachinery blades. It includes a steady, time domain, and harmonic balance flow solver. COSA has primarily been parallelised using MPI, but there is also a hybrid parallelisation that adds OpenMP functionality to the MPI parallelisation to enable larger number of cores to be utilised for a given simulation as the MPI parallelisation is limited to the number of geometric partitions (or blocks) in the simulation, or to exploit multi-threaded hardware where appropriate. This paper outlines the work undertaken to optimise these two parallelisation strategies, improving the efficiency of both and therefore reducing the computational time required to compute simulations. We also analyse the power consumption of the code on a range of leading HPC systems to further understand the performance of the code., Comment: Submitted to the SC13 conference, 10 pages with 8 figures

Published
2013

13. Numerical and Experimental Analysis of the Cold Flow Physics of a Nonpremixed Industrial Gas Burner.

Author

Ortolani, A., Yeadon, J., Ruane, B., Paul, M., and Campobasso, M. S.

Subjects
INDUSTRIAL gases, COMPUTATIONAL fluid dynamics, FLUID dynamics, GAS dynamics, BOUNDARY layer (Aerodynamics), REYNOLDS stress
Abstract

The flow field of a nonpremixed industrial gas burner is analyzed with Reynolds-averaged Navier-Stokes computational fluid dynamics validated against velocity and pressure measurements. Combustion is not modeled because the aim is optimizing the predictive capabilities of the cold flow before including chemistry. The system's complex flow physics, affected by a 90 deg turn, backward and forward facing steps, and transversal jets in the mainstream is investigated at full and partial load. The sensitivity of the computed flow field to inflow boundary condition setup, approach for resolving/modeling wall-bounded flows, and turbulence closure is assessed. In the first sensitivity analysis, the inflow boundary condition is prescribed using measured total pressure or measured velocity field. In the second, boundary layers are resolved down to the wall or modeled with wall functions. In the third sensitivity analysis, the turbulence closure uses the k-ω shear stress transport eddy viscosity model or two variants of the Reynolds stress model. The agreement between the predictions of most simulation setups among themselves and with the measurements is good. For a given type of inflow condition and wall flow treatment, the ω-based Reynolds stress model gives the best agreement with measurements among the considered turbulence models at full load. At partial load, the comparison with measured data highlights some scatter in the predictions of different patterns of the flow measurements. Overall, the findings of this study provide insight into the fluid dynamics of industrial gas burners and guidelines for their simulation-based analysis. [ABSTRACT FROM AUTHOR]

Published
2023
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17. Stabilizing linear harmonic flow solvers for turbomachinery aeroelasicity with complex iterative algorithms

Author

Campobasso, M. Sergio and Giles, Michael B.

Subjects
Algorithms -- Usage, Aeronautics -- Analysis, Turbomachines -- Analysis, Algorithm, Aerospace and defense industries, Business
Abstract

The linear flow analysis of turbomachinery aeroelasticity views the unsteady flow as the sum of a background nonlinear flowfield and a linear harmonic perturbation. The background state is usually determined by solving the nonlinear steady-flow equations. The flow solution representing the amplitude and phase of the unsteady perturbation is given by the solution of a large complex linear system that results from the linearization of the time-dependent nonlinear equations about the background state. The solution procedure of the linear harmonic Euler/Navier-Stokes solver of the HYDRA suite of parallel FORTRAN codes consists of a preconditioned multigrid iteration that in some circumstances becomes numerically unstable. The results of previous investigations have already pointed at the physical origin of these numerical instabilities and have also demonstrated the code stabilization achieved by using the real GMRES and RPM algorithms to stabilize the existing preconditioned multigrid iteration. This approach considered an equivalent augmented real form of the original complex system of equations. We summarize the implementation of the complex GMRES and RPM algorithms that are applied directly to the solution of the complex harmonic equations. Results show that the complex solvers not only stabilize the code, but also lead to a substantial enhancement of the computational performance with respect to their real counterparts. The results of a nonlinear unsteady calculation that further emphasize the physical origin of the numerical instabilities are also reported.

Published
2006

26. The prothrombin time/international normalized ratio (PT/INR) Line: derivation of local INR with commercial thromboplastins and coagulometers – two independent studies

Author

POLLER L, IBRAHIM S, KEOWN M, PATTISON A, JESPERSEN J, EUROPEAN ACTION ON A.N.T.I.C.O.A.G.U.L.A.T.I.O.N. COLLABORATORS: MARUN S, MUNTEAN W, ASPÖCK G, BAILLEUL E, WIJNS W, MICHEL T, JOCHMANS K, CHATELAIN B, MARCELIS L, NIJS AN, JOHNSTON M, KYNDE K, SYRÄJLÄ M, SAVOLAINEN ER, IVASKA K, RAJAMÄKI A, VANHARANTA R, JUHAN I, AILLAUD MF, GUILLIN MC, HUISSE MG, SIE P, LECOMPTE T, SCHMITT Y, HARENBERG J, PLESCH W, ARONIS S, THEODOSSIADES G, TSOUKANAS B, MARKALA D, DITSA M, CAHILL M, MADDEN M, FITZGERALD H, MCCARTHY D, COLLINS B, ROONEY S, NAPARSTEK E, MARONGIU F, ERBA N, TESTA S, MARIANI G, POTÌ R, MANNUCCI PM, TRIPODI A, BADER R, PENGO V, GRESELE P, D'INCÀ M, AGENO W, TOSETTO A, HENSGENS HE, IDEMA RN, OOSTERHOUT DH, MULDER AB, HAMULYAK K, VD DUSSEN H, MUSIAL J, GAGO T, PALMEIRO A, CAMPOS M, MARQUES DIAS DA, CUNHA MONTEIRO Á, ANGELA CUNHA M, DE GAIA WN, PETERNEL P, STEGNAR M, FONTCUBERTA J, BORRELL M, REVERTER JC, SANTASUSANA PD, LOPEZ FERNANDEZ MF, MONTERO J, RIBERA CASADO C, VICENTE V, EDLUND B, EGBERG N, LÄMMLE B, ALBERIO L, DE MOERLOOSE P, REBER G, MACHIN SJ, MACKIE I, LAWRIE A, LUCKIT J, SHANKS D, DOLAN G, FLAHERTY T, LUDLAM CA, WALKER ID, LAWSON DE, TRISCOTT M, MARLAR RA, HEIT JA, WATZKE H, WEISSER B, GALLUS AS, OSMOND J, CORNET I, MUNSTER AM, LEED B, CHILLOU C, DEFARD M, HORELLOU MH, HALKIN H, LOEBSTEIN R, KIRGNER I, DENTALI F, TRAPANI LOMBARDO V, SOTTILOTTA G, CONSIGLIO P, DE MICHELE S, MOIA M, CARPENEDO M, OLIVIERO B, MANOTTI C, TASSONI MI, PALARETI G, BRUSI C, LEGNANI C, PEGORARO C, ANDRIANI C, GRAZIA CIRIGLIANO M, RIBALDI E, ABBATE R, POLI D, PERRICONE C, SCHIAVULI M, CASIERA C, LUPONE MR, ROSSI E, CRIVELLI S, BIROLINI A, PARENTE F, MIGLIETTA AM, CAMPOBASSO M, SYDOR W, KREVEL B, FERNANDEZ MA, LOZANO M, SHIACH C, BOWYER C, CHARLES F., PALARETI, GUALTIERO, COSMI, BENILDE, POLLER L, IBRAHIM S, KEOWN M, PATTISON A, JESPERSEN J, EUROPEAN ACTION ON ANTICOAGULATION. COLLABORATORS: MARUN S, MUNTEAN W, ASPÖCK G, BAILLEUL E, WIJNS W, MICHEL T, JOCHMANS K, CHATELAIN B, MARCELIS L, NIJS AN, JOHNSTON M, KYNDE K, SYRÄJLÄ M, SAVOLAINEN ER, IVASKA K, RAJAMÄKI A, VANHARANTA R, JUHAN I, AILLAUD MF, GUILLIN MC, HUISSE MG, SIE P, LECOMPTE T, SCHMITT Y, HARENBERG J, PLESCH W, ARONIS S, THEODOSSIADES G, TSOUKANAS B, MARKALA D, DITSA M, CAHILL M, MADDEN M, FITZGERALD H, MCCARTHY D, COLLINS B, ROONEY S, NAPARSTEK E, PALARETI G, MARONGIU F, ERBA N, TESTA S, MARIANI G, POTÌ R, MANNUCCI PM, TRIPODI A, BADER R, PENGO V, GRESELE P, D'INCÀ M, AGENO W, TOSETTO A, HENSGENS HE, IDEMA RN, OOSTERHOUT DH, MULDER AB, HAMULYAK K, VD DUSSEN H, MUSIAL J, GAGO T, PALMEIRO A, CAMPOS M, MARQUES-DIAS DA, CUNHA MONTEIRO Á, ANGELA CUNHA M, DE GAIA WN, PETERNEL P, STEGNAR M, FONTCUBERTA J, BORRELL M, REVERTER JC, SANTASUSANA PD, LOPEZ-FERNANDEZ MF, MONTERO J, RIBERA CASADO C, VICENTE V, EDLUND B, EGBERG N, LÄMMLE B, ALBERIO L, DE MOERLOOSE P, REBER G, MACHIN SJ, MACKIE I, LAWRIE A, LUCKIT J, SHANKS D, DOLAN G, FLAHERTY T, LUDLAM CA, WALKER ID, LAWSON DE, TRISCOTT M, MARLAR RA, HEIT JA, WATZKE H, WEISSER B, GALLUS AS, OSMOND J, CORNET I, MUNSTER AM, LEED B, CHILLOU C, DEFARD M, HORELLOU MH, HALKIN H, LOEBSTEIN R, KIRGNER I, DENTALI F, TRAPANI LOMBARDO V, SOTTILOTTA G, CONSIGLIO P, DE MICHELE S, MOIA M, CARPENEDO M, OLIVIERO B, MANOTTI C, TASSONI MI, COSMI B, BRUSI C, LEGNANI C, PEGORARO C, ANDRIANI C, GRAZIA CIRIGLIANO M, RIBALDI E, ABBATE R, POLI D, PERRICONE C, SCHIAVULI M, CASIERA C, LUPONE MR, ROSSI E, CRIVELLI S, BIROLINI A, PARENTE F, MIGLIETTA AM, CAMPOBASSO M, SYDOR W, KREVEL B, FERNANDEZ MA, LOZANO M, SHIACH C, BOWYER C, CHARLES F., Interne Geneeskunde, Biochemie, and RS: CARIM School for Cardiovascular Diseases

Subjects
INR correction, endocrine system, medicine.medical_specialty, coagulometers, Prothrombin Time/*standard, Reproducibility of Result, PT, World Health Organization, International Normalized Ratio/*standard, Thromboplastin, Automation, Laboratory/standard, ECAA plasmas, Predictive Value of Tests, health services administration, medicine, Animals, Humans, heterocyclic compounds, International Normalized Ratio, cardiovascular diseases, thromboplastins, Blood Coagulation, Reference standards, Mathematics, Automation, Laboratory, Observer Variation, Prothrombin time, Analysis of Variance, medicine.diagnostic_test, business.industry, fungi, Reproducibility of Results, Hematology, Reference Standards, Surgery, INR Line, Multicenter study, Calibration, Linear Models, Prothrombin Time, Cattle, Rabbits, Observer variation, Nuclear medicine, business
Abstract

The WHO scheme for prothrombin time (PT) standardization has been limited in application, because of its difficulties in implementation, particularly the need for mandatory manual PT testing and for local provision of thromboplastin international reference preparations (IRP).The value of a new simpler procedure to derive international normalized ratio (INR), the PT/INR Line, based on only five European Concerted Action on Anticoagulation (ECAA) calibrant plasmas certified by experienced centres has been assessed in two independent exercises using a range of commercial thromboplastins and coagulometers. INRs were compared with manual certified values with thromboplastin IRP from expert centres and in the second study also with INRs from local ISI calibrations.In the first study with the PT/INR Line, 8.7% deviation from certified INRs was reduced to 1.1% with human reagents, and from 7.0% to 2.6% with rabbit reagents. In the second study, deviation was reduced from 11.2% to 0.4% with human reagents by both local ISI calibration and the PT/INR Line. With rabbit reagents, 10.4% deviation was reduced to 1.1% with both procedures; 4.9% deviation was reduced to 0.5% with bovine/combined reagents with local ISI calibrations and to 2.9% with the PT/INR Line. Mean INR dispersion was reduced with all thromboplastins and automated systems using the PT/INR Line.The procedure using the PT/INR Line provides reliable INR derivation without the need for WHO ISI calibration across the range of locally used commercial thromboplastins and automated PT systems included in two independent international studies.? 2010 International Society on Thrombosis and Haemostasis.

Published
2011

27. Flutter and Forced Response of Mistuned Turbomachinery

Author

Campobasso, M and Giles, M

Abstract

This report reviews the mathematical analysis of mistuned aeroelasticity in turbomachines, avoiding excessive mathematical complexity, and putting the emphasis on the physical interpretation of the mathematics. The aeroelastic behaviour can be analysed either by considering the motion of individual blades or by considering a sum of travelling wave modes. The modal viewpoint is shown to be most suitable when the degree of mistuning is small. On the other hand, the blade viewpoint is more natural when the structural mistuning is larger than the aerodynamic coupling, resulting in highly localised eigenmodes. Asymptotic analyses are used to enlighten the physical mechanisms through which structural mistuning affects flutter and forced response, and their accuracy is assessed by comparison with the exact solution obtained by direct numerical computation. Numerical results illustrate the transition from travelling wave modes to localised vibration as the degree of mistuning increases, demonstrate the stabilising effect of mistuning on blade flutter and help explaining the dependence of the peak blade response on the order of the excitation in mistuned rotors. Monte Carlo simulations are carried out for randomly mistuned blades to draw conclusions on the expected effects of the mistuning. This research was supported by Rolls-Royce plc and EPSRC and this report is an expanded version of a paper presented at the ISUAAAT 2000 Conference in Lyon, France on September 4-8, 2000

Published
2016

40. Aerodynamic design optimization of wind turbine rotors under geometric uncertainty.

Author

Campobasso, M. Sergio, Minisci, Edmondo, and Caboni, Marco

Subjects
WIND turbines, ROTORS, AEROFOILS, AIRPLANE design, MONTE Carlo method, UNIVARIATE analysis, STOCHASTIC analysis
Abstract

Presented is a robust optimization strategy for the aerodynamic design of horizontal axis wind turbine rotors including the variability of the annual energy production because of the uncertainty of the blade geometry caused by manufacturing and assembly errors. The energy production of a rotor designed with the proposed robust optimization approach features lower sensitivity to stochastic geometry errors with respect to that of a rotor designed with the conventional deterministic optimization approach that ignores these errors. The geometry uncertainty is represented by normal distributions of the blade pitch angle, and the twist angle and chord of the airfoils. The aerodynamic module is a blade-element momentum theory code. BothMonte Carlo sampling and the univariate reduced quadrature technique, a novel deterministic uncertainty analysis method, are used for uncertainty propagation. The performance of the two approaches is assessed in terms of accuracy and computational speed. A two-stage multi-objective evolution-based optimization strategy is used. Results highlight that, for the considered turbine type, the sensitivity of the annual energy production to rotor geometry errors can be reduced by reducing the rotational speed and increasing the blade loading. The primary objective of the paper is to highlight how to incorporate an efficient and accurate uncertainty propagation strategy in wind turbine design. The formulation of the considered design problem does not include all the engineering constraints adopted in real turbine design, but the proposed probabilistic design strategy is fairly independent of the problem definition and can be easily extended to turbine design systems of any complexity. [ABSTRACT FROM AUTHOR]

Published
2016
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