17 research outputs found
Optimization of morphing flaps based on fluid structure interaction modeling
No full textThis article describes the design optimization of morphing trailing edge flaps for wind turbines with ‘smart blades’. A high fidelity Fluid Structure Interaction (FSI) simulation framework is utilized, comprised of 2D Finite Element Analysis (FEA) and Computational Fluid Dynamics (CFD) models. A coupled aero-structural simulation of a 10% chordwise length morphing trailing edge flap for a 4 MW wind turbine rotor is carried out and response surfaces are produced with respect to the flap internal geometry design parameters for the design conditions. Surrogate model based optimization is applied in order to converge to a flap design, which maximizes aerodynamic lift control performance while minimizing drag penalty, subject to material strength and manufacturing constraints. The purely structural optimization of the flap response is compared to the coupled aerostructural optimization
Computational fluid dynamics-based surrogate optimization of a wind turbine blade tip extension for maximising energy production
No full textThis article presents a design study into the redesign of a wind turbine blade tip seeking to increase the energy production subject to the loads constraints of the existing blade. The blade shape is parameterized to allow for planform changes in the tip region with respect to chord, twist and blade length extension, and additionally three parameters that allow to explore winglet-like shapes. The design strategy uses 3D computational fluid dynamics computations of the geometrically resolved rotor to create a surrogate model, after which the tip shape is numerically optimized based on the surrogate model, subject to a number of geometric and loads-based constraints. The study shows that it is possible to increase power production by 2.6% for a blade extension with a winglet, without increasing the flapwise bending moment at 90% radius, whereas for a straight blade extension it was only possible to achieve an increase of 0.76%
Aeroelastic Optimization of a 10 MW Wind Turbine Blade with Active Trailing Edge Flaps
No full textThis article presents the aeroelastic optimization of a 10MW wind turbine ‘smart blade’ equipped with active trailing edge flaps. The multi-disciplinary wind turbine analysis and optimization tool HawtOpt2 is utilized, which is based on the open-source framework Open-MDAO. The tool interfaces to several state-of-the art simulation codes, allowing for a wide variety of problem formulations and combinations of models. A simultaneous aerodynamic and structural optimization of a 10 MW wind turbine rotor is carried out with respect to material layups and outer shape. Active trailing edge flaps are integrated in the design taking into account their achieved fatigue load reduction. The optimized ‘smart blade’ design is compared to an aeroelastically optimized design with no flaps and the baseline design
Field testing of morphing flaps on a wind turbine blade using an outdoor rotating rig
No full textIn recent years, active flap devices on wind turbine blades have been shown to both reduce peak loads at the tower and extend blade fatigue life. Associated benefits include retrofitting existing tower infrastructure with longer and greater energy-producing blades whilst also extending service life of blades. In the current work, a novel wind turbine blade control method using morphing flaps has been successfully investigated and demonstrated using a scaled demonstrator mounted on an outdoor rotating test rig. Shape adaptive structures that remain conformal to the flow are increasingly referred to as morphing devices. As part of the INNWind.eu project, a novel morphing flap device was developed for a recently designed aerofoil. The proposed morphing flap comprises a light-weight carbon fibre laminate, 3D printed honeycomb core and a flexible silicone surface. A comprehensive test campaign using an outdoor rotating test rig under atmospheric conditions was carried out to assess the potential effectiveness. As shown by experimental data, the morphing flap provides good performance in terms of aerodynamic lift control of the blade and can provide dynamic load alleviation capability
A System Dynamics Model of Cyclical Office Oversupply
No full textThis article explores office market system dynamics through a simple simulation model. Model lag and adjustment parameters similar to real office markets generate explosive cycles. Simulations show that deviations from equilibrium can be reduced by changing the information structure of the system. System dynamics, principle/agent conflicts, a prisoners’ dilemma game, faulty information (poor forecasting, market research and valuation techniques), regulatory institutions, and differing equilibria in office space and financial markets all contribute to allocative inefficiency. Thinking of office markets as a "managed feedback control system" may be a useful representation of the oversupply problem. Leverage points for system improvement may be a municipal "queue" to address agency and prisoner's dilemma problems, improved forecasting techniques and more reliance on forecasting.
Decision by sampling
No full textWe present a theory of decision by sampling (DbS) in which, in contrast with traditional models, there are no underlying psychoeconomic scales. Instead, we assume that an attribute’s subjective value is constructed from a series of binary, ordinal comparisons to a sample of attribute values drawn from memory and is its rank within the sample. We assume that the sample reflects both the immediate distribution of attribute values from the current decision’s context and also the background, real-world distribution of attribute values. DbS accounts for concave utility functions; losses looming larger than gains; hyperbolic temporal discounting; and the overestimation of small probabilities and the underestimation of large probabilities
Decision by sampling
No full textWe present a theory of decision by sampling (DbS) in which, in contrast with traditional
models, there are no underlying psychoeconomic scales. Instead, we assume that an
attribute's subjective value is constructed from a series of binary, ordinal comparisons to a
sample of attribute values drawn from memory and is its rank within the sample. We assume
that the sample reflects both the immediate distribution of attribute values from the current
decision's context and also the background, real-world distribution of attribute values. DbS
accounts for concave utility functions; losses looming larger than gains; hyperbolic temporal
discounting; and the overestimation of small probabilities and the underestimation of large
probabilities
Probing color coherence effects in pp collisions at √s = 7 TeV
No full textOpen Access This article is distributed under the terms of the Creative Commons Attribution License which permits any use, distribution, and reproduction in any medium, provided the original author(s) and the
source are credited. Funded by SCOAP3 / License Version CC BY 4.0.A study of color coherence effects in pp collisions at a center-of-mass energy of 7TeV is presented. The data used in the analysis were collected in 2010 with the CMS detector at the LHC and correspond to an integrated luminosity of 36 pb-1. Events are selected that contain at least three jets and where the two jets with the largest transverse momentum exhibit a back-to-back topology. The measured angular correlation between the second- and third-leading jet is shown to be sensitive to color coherence effects, and is compared to the predictions of Monte Carlo models with various implementations of color coherence. None of the models describe the data satisfactorily.BMWF and FWF (Austria); FNRS and FWO(Belgium); CNPq, CAPES, FAPERJ, and FAPESP (Brazil);MES
(Bulgaria); CERN; CAS, MoST, and NSFC (China); COLCIENCIAS (Colombia); MSES (Croatia); RPF(Cyprus); MoER, SF0690030s09 and ERDF (Estonia); Academy of Finland, MEC, and HIP (Finland);
CEA and CNRS/IN2P3 (France); BMBF, DFG, and HGF (Germany); GSRT (Greece); OTKA and NIH (Hungary); DAE and DST (India); IPM (Iran); SFI (Ireland); INFN (Italy); NRF and WCU (Republic of
Korea); LAS (Lithuania); CINVESTAV, CONACYT, SEP, andUASLPFAI (Mexico); MBIE (New Zealand); PAEC (Pakistan); MSHE and NSC (Poland); FCT (Portugal); JINR (Dubna); MON, RosAtom, RAS and RFBR(Russia);MESTD (Serbia); SEIDI and CPAN(Spain); Swiss Funding Agencies (Switzerland); NSC (Taipei); ThEPCenter, IPST, STAR and NSTDA (Thailand); TUBITAK and TAEK (Turkey); NASU (Ukraine); STFC (United Kingdom); DOE and NSF (USA)
Studies of dijet transverse momentum balance and pseudorapidity distributions in pPb collisions at √sNN=5.02 TeV
No full textOpen Access This article is distributed under the terms of the Creative Commons Attribution License which permits any use, distribution, and reproduction in any medium, provided the original author(s) and the
source are credited. Funded by SCOAP3 / License Version CC BY 4.0.Dijet production has been measured in pPb collisions at a nucleon–nucleon centre-of-mass energy of 5.02 TeV . A data sample corresponding to an integrated luminosity of 35 nb −1 was collected using the Compact Muon Solenoid detector at the Large Hadron Collider. The dijet transverse momentum balance, azimuthal angle correlations, and pseudorapidity distributions are studied as a function of the transverse energy in the forward calorimeters ( E 4<|η|<5.2 T ). For pPb collisions, the dijet transverse momentum ratio and the width of the distribution of dijet azimuthal angle difference are comparable to the same quantities obtained from a simulated pp reference and insensitive to E 4<|η|<5.2 T . In contrast, the mean value of the dijet pseudorapidity is found to change monotonically with increasing E 4<|η|<5.2 T , indicating a correlation between the energy emitted at large pseudorapidity and the longitudinal motion of the dijet frame. The pseudorapidity distribution of the dijet system in minimum bias pPb collisions is compared with next-to-leading-order perturbative QCD predictions obtained from both nucleon and nuclear parton distribution functions, and the data more closely match the latter
Measurement of WZ and ZZ production in pp collisions at √s = 8 TeV in final states with b-tagged jets
No full textOpen Access This article is distributed under the terms of the Creative
Commons Attribution License which permits any use, distribution, and
reproduction in any medium, provided the original author(s) and the
source are credited.
Funded by SCOAP3 / License Version CC BY 4.0.Measurements are reported of the WZ and ZZ production cross sections in proton-proton collisions at s √ =8 TeV in final states where one Z boson decays to b-tagged jets. The other gauge boson, either W or Z, is detected through its leptonic decay (either W→eν , μν or Z→e + e − , μ + μ − , or νν ¯ ). The results are based on data corresponding to an integrated luminosity of 18.9 fb −1 collected with the CMS detector at the Large Hadron Collider. The measured cross sections, σ(pp→WZ)=30.7±9.3(stat.)±7.1(syst.)±4.1(th.)±1.0(lum.)pb and σ(pp→ZZ)=6.5±1.7(stat.)±1.0(syst.)±0.9(th.)±0.2(lum.)pb , are consistent with next-to-leading order quantum chromodynamics calculationsBMWF and FWF (Austria); FNRS and FWO (Belgium); CNPq, CAPES, FAPERJ, and FAPESP (Brazil);
MES (Bulgaria); CERN; CAS, MoST, and NSFC (China); COLCIENCIAS (Colombia); MSES and CS (Croatia); RPF (Cyprus); MoER, SF0690030s09 and ERDF (Estonia); Academy of Finland, MEC, and HIP (Finland); CEA and CNRS/IN2P3 (France); BMBF, DFG, and HGF(Germany);GSRT(Greece);OTKAand NIH(Hungary);DAEand DST (India); IPM (Iran); SFI (Ireland); INFN (Italy); NRF and WCU (Republic of Korea); LAS (Lithuania);MOE and UM(Malaysia); CINVESTAV, CONACYT, SEP, and UASLP-FAI (Mexico); MBIE (New Zealand); PAEC (Pakistan); MSHE and NSC (Poland); FCT (Portugal); JINR (Dubna); MON, RosAtom, RAS and RFBR (Russia); MESTD (Serbia); SEIDI and CPAN (Spain); Swiss Funding Agencies (Switzerland);
NSC (Taipei); ThEPCenter, IPST, STAR and NSTDA(Thailand); TUBITAK and TAEK (Turkey); NASU and SFFR (Ukraine); STFC (United Kingdom); DOE and NSF (USA)
