Large-Eddy Simulation and Conjugate Heat Transfer in a Round Impinging Jet

Shum-Kivan, Francis; Duchaine, Florent; Gicquel, Laurent

doi:10.1115/gt2014-25152

Cited by 17 publications

(17 citation statements)

References 37 publications

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“…A strong influence of the inlet profile on the fluctuating quantities was observed in this case. The results indicate an acceptable level of correlation with the experiments for the mean and turbulent quantities despite the relatively low resolution of the grid compared to the ones used in the literature [40,41,42]. The prediction of the mean axial and radial velocities are in good agreement with the experimental data.…”

Section: Cold Flow Validationsupporting

confidence: 65%

Heat Transfer Effects on a Fully Premixed Methane Impinging Flame

Mira

Zavala-Aké

Ávila

et al. 2016

Flow Turbulence Combust

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A numerical assessment of different thermal conditions for an impinging flame configuration is investigated using large-eddy simulation. The cases of study correspond to a turbulent methane flame at equivalence ratio ER=0.8 and temperature T=298K exiting at 30 m/s with a nozzle-to-plate distance over diameter of H/D = 2. Computational cases based on different thermal conditions are compared to a conjugate case, in which fluid and solid domains are solved simultaneously. A solid material defined with enhanced conductivity properties is used to represent the wall in the conjugate case, so that the characteristic time scales of the solid are reduced. The results indicate that the heat transfer condition influences not only the mean temperature and gradients, but also the temperature fluctuations in the near-wall region. It is found that adiabatic, isothermal and more sophisticated Robin-type boundary conditions contribute to underpredict/overpredict the temperature field near the wall. As the time scales of fluid and solid are of the same order, the use of conjugate approaches is required to predict the correct flow fields near the wall and the skin temperature.

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Section: Cold Flow Validationsupporting

confidence: 65%

Heat Transfer Effects on a Fully Premixed Methane Impinging Flame

Mira

Zavala-Aké

Ávila

et al. 2016

Flow Turbulence Combust

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“…The matching of numerical and experimental data for the radial Nusselt number distribution is usually poor, despite the free jet flow matches well with the experimental data [88,9,89]. In addition, either the secondary peak is not captured [9] or the location is not accurately computed [89]. Despite all the work done by many authors for decades, the CFD simulation of the heat transfer from impinging jets is still a challenging investigation that needs further research to answer critical questions [10].…”

Section: Results Of the Cfd Simulation At Different Configurationsmentioning

confidence: 95%

Two-step numerical simulation of the heat transfer from a flat plate to a swirling jet flow from a rotating pipe

Granados-Ortiz

Ortega-Casanova²,

Chen

2019

HFF

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Purpose Impinging jets have been widely studied, and the addition of swirl has been found to be beneﬁcial to heat transfer. As there is no literature on Reynolds-averaged Navier Stokes equations (RANS) nor experimental data of swirling jet flows generated by a rotating pipe, the purpose of this study is to ﬁll such gap by providing results on the performance of this type of design. Design/methodology/approach As the flow has a different behaviour at different parts of the design, the same turbulent model cannot be used for the full domain. To overcome this complexity, the simulation is split into two coupled stages. This is an alternative to use the costly Reynold stress model (RSM) for the rotating pipe simulation and the SST k-ω model for the impingement. Findings The addition of swirl by means of a rotating pipe with a swirl intensity ranging from 0 up to 0.5 affects the velocity profiles, but has no remarkable effect on the spreading angle. The heat transfer is increased with respect to a non-swirling flow only at short nozzle-to-plate distances H/D < 6, where H is the distance and D is the diameter of the pipe. For the impinging zone, the highest average heat transfer is achieved at H/D = 5 with swirl intensity S = 0.5. This is the highest swirl studied in this work. Research limitations/implications High-fidelity simulations or experimental analysis may provide reliable data for higher swirl intensities, which are not covered in this work. Practical implications This two-step approach and the data provided is of interest to other related investigations (e.g. using arrays of jets or other surfaces than flat plates). Originality/value This paper is the first of its kind RANS simulation of the heat transfer from a flat plate to a swirling impinging jet flow issuing from a rotating pipe. An extensive study of these computational fluid dynamics (CFD) simulations has been carried out with the emphasis of splitting the large domain into two parts to facilitate the use of different turbulent models and periodic boundary conditions for the flow confined in the pipe.

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“…This specific configuration is known to lead to a double peak in the plate Nusselt number distribution. 13,16,22,24 Several experimental studies have dealt with this setup and heat transfer results are not always in agreement. For example, for similar flow configurations and similar injection nozzles, i.e., long straight round pipe, the first peak in the radial Nusselt distribution is either found at the stagnation point 16,27,33 or near r/D = 0.5.…”

Section: Flow Configuration and Available Experimental Datamentioning

confidence: 99%

“…Heat transfer characteristics of impinging jets have been extensively studied experimentally 5,15-20 and numerically. 13,[21][22][23][24] For a single jet, there are three main parameters that govern heat transfer: the Reynolds number, 17 Re = U b D/ν, where ν is the kinematic viscosity, the nozzle to plate distance 16,25 H, and the mean velocity profile at the nozzle outlet [26][27][28] which is different for different nozzle geometries for example. For "sufficiently high" Reynolds numbers and low nozzle to plate distance, i.e., H/D < 4, one interesting feature is the non-monotonic variation of the radial distribution of the mean wall heat transfer with the presence of two distinct peaks.…”

Section: Introductionmentioning

confidence: 99%

Secondary peak in the Nusselt number distribution of impinging jet flows: A phenomenological analysis

et al. 2016

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This paper focuses on a wall-resolved Large Eddy Simulation (LES) of an isothermal round submerged air jet impinging on a heated flat plate, at a Reynolds number of 23 000 (based on the nozzle diameter and the bulk velocity at the nozzle outlet) and for a nozzle to plate distance of two jet diameters. This specific configuration is known to lead to a non-monotonic variation of the temporal-mean Nusselt number as a function of the jet center distance, with the presence of two distinct peaks located on the jet axis and close to two nozzle diameters from the jet axis. The objectives are here twofold: first, validate the LES results against experimental data available in the literature and second to explore this validated numerical database by the use of high order statistics such as skewness and probability density functions of the temporal distribution of temperature and pressure to identify flow features at the origin of the second Nusselt peak. Skewness (Sk) of the pressure temporal distribution reveals the rebound of the primary vortices located near the location of the secondary peak and allows to identify the initiation of the unsteady separation linked to the local minimum in the mean heat transfer distribution. In the region of mean heat transfer enhancement, joint velocity-temperature analyses highlight that the most probable event is a cold fluid flux towards the plate produced by the passage of the vortical structures. In parallel, heat transfer distributions, analyzed using similar statistical tools, allow to connect the above mentioned events to the heat transfer on the plate. Thanks to such advanced analyses, the origin of the double peak is confirmed and connected to the flow dynamics. Published by AIP Publishing.

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Large-Eddy Simulation and Conjugate Heat Transfer in a Round Impinging Jet

Cited by 17 publications

References 37 publications

Heat Transfer Effects on a Fully Premixed Methane Impinging Flame

Heat Transfer Effects on a Fully Premixed Methane Impinging Flame

Two-step numerical simulation of the heat transfer from a flat plate to a swirling jet flow from a rotating pipe

Secondary peak in the Nusselt number distribution of impinging jet flows: A phenomenological analysis

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