Article
Thermodynamics
Michael Severin, Oliver Lammel, Wolfgang Meier
Summary: A preheated premixed CH4/air jet flame was studied in an optically accessible rectangular combustion chamber to understand flame stabilization and expansion mechanisms. A lateral recirculation zone formed in the combustion chamber due to the off-center position of the jet, stabilizing the lifted flame. Measurements of the flow field, OH concentration, and heat release provided insights into the interaction between the flow field and the flame.
COMBUSTION AND FLAME
(2022)
Article
Mechanics
Shabnam Mohammadshahi, Hadi Samsam-Khayani, Zhiwen Deng, Kyung Chun Kim
Summary: This study investigated the velocity distribution and flow dynamics of oscillating jets in confined and non-confined channels, finding that the oscillation frequency is independent of the external domain, while the spreading angle is affected by Reynolds number and AR, leading to the formation of vortices in the confined external domain.
EUROPEAN JOURNAL OF MECHANICS B-FLUIDS
(2021)
Article
Energy & Fuels
Taiyu Wang, Zhenguo Wang, Jianguo Tan, Mingbo Sun, Zun Cai, Yao Liu
Summary: This study investigated the combustion characteristics of a highly-turbulent premixed jet flame influenced by a confined space. The results showed that the flame characteristics at different distances were comprehensively investigated, and a critical value for flame extinction was identified. The flame structures were classified into V-shaped flame, converging flame, and fully developed flame. The presence of intense combustion regions related to CH* and OH* reactions was observed in the confined space.
Article
Engineering, Mechanical
Katherine Kokmanian, Diogo C. Barros, Marcus Hultmark, Pierre Dupont
Summary: The S-NSTAP probe was deployed in a supersonic wind tunnel to gather data on freestream and boundary layer measurements at M-infinity = 2, showing superior temporal resolution compared to conventional hot-wires. Sensitivity coefficients varied between probes, with the S-NSTAP exhibiting a coefficient half the size of the conventional probe, and experimental data were compared to numerically modeled results for turbulent boundary layers.
EXPERIMENTS IN FLUIDS
(2021)
Article
Mechanics
Clayton P. Byers, Marcus Hultmark, Ivan Marusic, Matt K. Fu
Summary: Highly resolved, two-component velocity measurements were conducted near the centerline of turbulent pipe flow. Data obtained with a nanoscale cross-wire probe were used to examine the inertial subrange scaling of the longitudinal and transverse velocity components. Corrections for radial inhomogeneities at the centerline improved the behavior of the third-order structure functions in the pipe flow domain according to classical theories.
JOURNAL OF FLUID MECHANICS
(2021)
Article
Energy & Fuels
D. B. Proud, M. J. Evans, Q. N. Chan, P. R. Medwell
Summary: Combustion in hot and low oxygen environments, particularly in terms of the effects of pressure, is not fully understood. In this study, a new burner has been developed for the investigation of flame stabilization, structure, and soot formation at elevated pressures.
JOURNAL OF THE ENERGY INSTITUTE
(2022)
Article
Chemistry, Multidisciplinary
Bostjan Zajec, Marko Matkovic, Nejc Kosanic, Jure Oder, Blaz Mikuz, Jan Kren, Iztok Tiselj
Summary: This paper investigates the comparison of two very accurate approaches, PIV and DNS, in 3D turbulent flow experiments, aiming to reveal the similarities and differences between the two methods in the same cross-section geometry.
APPLIED SCIENCES-BASEL
(2021)
Article
Mechanics
M. Gauding, M. Bode, Y. Brahami, E. Varea, L. Danaila
Summary: The study investigates the combined effect of internal and external intermittency on the statistical properties of temporally evolving planar turbulent jet flows at different Reynolds numbers. The analysis shows that structure functions exhibit self-preservation in both the core and shear layer of the jet, regardless of the normalization scales used. The impact of external intermittency on small-scale turbulence is demonstrated by a growing departure from self-similarity towards the flow edge.
JOURNAL OF FLUID MECHANICS
(2021)
Article
Mechanics
P. Salizzoni, S. Vaux, M. Creyssels, M. Amielh, L. Pietri, F. Anselmet
Summary: In this study, the dynamics of a low-density round jet are investigated through theoretical analysis, laboratory experiments and numerical simulations. The results reveal the mechanisms governing turbulent momentum and mass transfers, as well as the entrainment of ambient fluid. The role of varying conditions at the source, such as the shape of the inlet velocity profile and the presence of a bottom wall, are also examined. Despite the influence of reduced density on flow statistics, the entrainment rate shows little sensitivity to varying source conditions.
JOURNAL OF FLUID MECHANICS
(2023)
Article
Acoustics
Chung-Hao Ma, Manuj Awasthi, Danielle Moreau, Con Doolan
Summary: This paper presents a combined experimental and numerical study on the aeroacoustics of low Mach number turbulent flow over a forward-backward facing step (FBS). The study investigates the influence of step length and aspect ratio on wall pressure fluctuations and noise production. The results show that the largest wall pressure fluctuations occur slightly downstream of the step leading edge and turbulence interactions contribute to the wall pressure fluctuations in the on-step reattachment region. Aeroacoustic beamforming results show that the dominant noise source is located at the step leading edge.
JOURNAL OF SOUND AND VIBRATION
(2023)
Article
Mechanics
Moritz Sieber, C. Oliver Paschereit, Kilian Oberleithner
Summary: A method is proposed to estimate the properties of global hydrodynamic instability in turbulent flows by analyzing measurement data of limit-cycle oscillations. The flow dynamics are separated into deterministic and stochastic contributions, with models developed to account for the interaction between the two. The methodology is applied to a turbulent swirling jet to identify the supercritical Hopf bifurcation and demonstrate the identification of flow state from stationary measurements.
JOURNAL OF FLUID MECHANICS
(2021)
Article
Thermodynamics
Yang Liu, Jiatong Liu, Shu Li, Guohui Li, Lixing Zhou
Summary: A new particle subgrid scale model is proposed to consider the effect of gas flow on particle motions. A second-order moment two-phase turbulence model is used to model multiphase gas-particle turbulent flow, with a four-way coupling strategy to describe the interactions among gas-particle, particle-gas, and particle-particle collisions. Results show that predictions are well agreed with experimental data, and there are significant differences in vortex structures and distributions between gas and particle flow in swirling and non-swirling conditions.
Article
Mechanics
Timo Buschhagen, Rohan M. Gejji, Carlo Scalo, Carson D. Slabaugh
Summary: The dynamic response of a confined, premixed turbulent jet flame is investigated at high thermal power densities and turbulence levels. Multiple instability modes were observed, and high-frequency combustion instabilities were found to be associated with the azimuthal hydrodynamic mode of the reactant jet.
Article
Thermodynamics
Duna T. Yaseen, Amani J. Majeed, Muneer A. Ismael
Summary: This paper investigates the mixed convection heat transfer and fluid-structure interaction (FSI) of a hot cylinder placed in a backward-step channel. The influence of different configurations of a flexible step on cooling performance was evaluated. Results showed that adjusting the flexibility of the step can improve heat transfer performance and fluid dynamics at low Reynolds number.
THERMAL SCIENCE AND ENGINEERING PROGRESS
(2022)
Article
Astronomy & Astrophysics
S. Dupourque, N. Clerc, E. Pointecouteau, D. Eckert, S. Ettori, F. Vazza
Summary: By analyzing X-ray surface brightness fluctuations, this study aims to understand the structure of turbulence in the intracluster medium, which can improve the determination of galaxy cluster mass and enhance our understanding of their dynamic assembly.
ASTRONOMY & ASTROPHYSICS
(2023)
Article
Mechanics
Francois Beaubert, Halldor Palsson, Sylvain Lalot, Isabelle Choquet, Hadrien Bauduin
COMPTES RENDUS MECANIQUE
(2015)
Article
Engineering, Multidisciplinary
F. Beaubert, H. Palsson, S. Lalot, I. Choquet, H. Bauduin
APPLIED MATHEMATICAL MODELLING
(2016)
Article
Engineering, Electrical & Electronic
Fahd Boukrouche, Christophe Moreau, Julien Pelle, Francois Beaubert, Souad Harmand, Olivier Moreau
IEEE TRANSACTIONS ON POWER DELIVERY
(2017)
Article
Thermodynamics
Nicolas Lancial, Federico Torriano, Francois Beaubert, Souad Harmand, Gilles Rolland
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2017)
Article
Thermodynamics
F. Torriano, N. Lancial, M. Levesque, G. Rolland, C. Hudon, F. Beaubert, J. -F. Morissette, S. Harmand
APPLIED THERMAL ENGINEERING
(2014)
Article
Thermodynamics
Halldor Palsson, Francois Beaubert, Sylvain Lalot
HEAT TRANSFER ENGINEERING
(2013)
Article
Thermodynamics
B. Indurain, D. Uystepruyst, F. Beaubert, S. Lalot, A. Helgadottir
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
(2020)
Article
Thermodynamics
Bruce Indurain, Francois Beaubert, Sylvain Lalot, David Uystepruyst
Summary: Numerical simulations showed that swirling decaying flow generated by a novel axial guide vane swirler with profiled blades and no supporting device enhances heat transfer significantly, but also leads to higher pressure drop, with a higher Performance Evaluation Criterion.
HEAT TRANSFER ENGINEERING
(2021)
Article
Chemistry, Multidisciplinary
Asdis Helgadottir, Sylvain Lalot, Francois Beaubert, Halldor Palsson
APPLIED SCIENCES-BASEL
(2018)
Proceedings Paper
Engineering, Electrical & Electronic
N. Lancial, F. Torriano, F. Beaubert, S. Harmand, G. Rolland
2014 INTERNATIONAL CONFERENCE ON ELECTRICAL MACHINES (ICEM)
(2014)
Article
Engineering, Mechanical
L. Labraga, G. Kahissim, L. Keirsbulck, F. Beaubert
JOURNAL OF FLUIDS ENGINEERING-TRANSACTIONS OF THE ASME
(2007)
Article
Thermodynamics
F Beaubert, S Viazzo
INTERNATIONAL JOURNAL OF HEAT AND FLUID FLOW
(2003)
Article
Mechanics
F Beaubert, S Viazzo
COMPTES RENDUS MECANIQUE
(2002)
Article
Thermodynamics
Navid Freidoonimehr, Azadeh Jafari, Maziar Arjomandi
Summary: In this study, a high-fidelity flow visualisation technique is used to investigate the resemblance between a turbulent boundary layer generated by different tripping devices in a lab environment and a naturally developed canonical turbulent boundary layer. The study finds that the blockage created by trips is the main factor affecting the turbulence statistics at a certain downstream distance.
INTERNATIONAL JOURNAL OF HEAT AND FLUID FLOW
(2024)
Article
Thermodynamics
Yuning Wang, Alberto Solera-Rico, Carlos Sanmiguel Vila, Ricardo Vinuesa
Summary: This study proposes a method that combines 6-VAEs for modal decomposition and transformer neural networks for temporal-dynamics prediction in the latent space to develop reduced-order models (ROMs) for turbulent flows. The method achieves high reconstruction accuracy and accurate prediction of temporal dynamics.
INTERNATIONAL JOURNAL OF HEAT AND FLUID FLOW
(2024)
Article
Thermodynamics
L. Laguarda, S. Hickel, F. F. J. Schrijer, B. W. van Oudheusden
Summary: Wall-resolved large-eddy simulations were used to investigate the Reynolds number effects in supersonic turbulent boundary layers at Mach 2.0. The study covered a wide range of friction Reynolds numbers and identified trends in various statistics and scaling laws. The size and topology of turbulent structures in the boundary layer were examined, with a focus on the outer-layer motions at high Reynolds numbers. The study also assessed the influence of outer-layer structures on near-wall turbulence and the sensitivity of uniform momentum regions to compressibility.
INTERNATIONAL JOURNAL OF HEAT AND FLUID FLOW
(2024)
Article
Thermodynamics
A. Doehring, T. Kaller, S. J. Schmidt, N. A. Adams
Summary: In this study, well-resolved large-eddy simulations were used to investigate turbulent duct flows with a square cross section. The influence of a modified wall shear stress on the secondary flow was analyzed by artificially modifying the wall shear stress at one of the four walls. The results showed that the modification led to an asymmetrical distribution of the secondary flow source terms, affecting the momentum distribution. Furthermore, the anisotropy of the Reynolds stress tensor, which induces the secondary flow vortices, was significantly affected by the wall shear stress modulation.
INTERNATIONAL JOURNAL OF HEAT AND FLUID FLOW
(2024)
