Effect of inertial particles with different specific heat capacities on heat transfer in particle-laden turbulent flow

Tang, Shuai; Dong, Yuhong; Liu, Caixi

doi:10.1007/s10483-017-2224-9

Cited by 6 publications

(3 citation statements)

References 12 publications

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“…The density ratio of the dispersed phase to the carrier phase is large enough, and the particle diameter is smaller than the Kolmogorov length scale. Thus the most important force acting on the particle is the drag force exerted by the fluid [36]. In Lagrangian reference frame, the trajectory of a discrete phase droplet is predicted by integrating the force balance on the particle [34]:…”

Section: Reprinted With Permission Frommentioning

confidence: 99%

Experimental Characterization and Numerical Modelling of Urea Water Solution Spray in High-Temperature Crossflow for Selective Catalytic Reduction Applications

Khan¹,

Bjernemose²,

Lund³

2022

SAE J. STEEP

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Engines have improved a lot and reached a new state of the art in terms of combustion technology, but they alone still fall short in achieving emission limitations without any trade-off on performance. Selective Catalytic Reduction (SCR) is the key technology used to meet the increasingly strict Nitrogen Oxides (NOx) emission regulations. The injection of Urea Water Solution (UWS-32.5% urea solution) upstream the catalyst is currently the leading technique for reducing the emission of NOx from the exhaust (DeNOx). A uniform distribution of the spray droplets is very crucial to achieve a good conversion efficiency. Therefore, the size and velocity distribution of the droplets are of high importance in deciding the fate of the DeNOx process. This article describes an approach of modelling the UWS spray and its validation against experimental data collected under realistic exhaust-like conditions. Droplet size distributions and velocities were recorded using Phase Doppler Anemometry (PDA) in a high-temperature wind tunnel. Simulations of the spray were performed using a commercial Computational Fluid Dynamics (CFD) code, ANSYS Fluent, in Lagrangian solver framework under the same flow conditions.The results show that initializing the droplets with the correct diameter and velocity distributions is a vital element in determining the fate of droplets and their impingement location. Using the proposed methodology, validation of diameter and velocity distributions were performed and the average deviations in Sauter Mean Diameter (SMD) were found to be less than 8%. Deviations in velocity distributions were recorded with larger differences appearing in planes closer to the nozzle. It was seen that the simulation initiated with the correct momentum had an average difference of around 8% whereas the simulation initiated with a single velocity value had an average difference of around 32%, when compared with the actual measurement data.

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Section: Reprinted With Permission Frommentioning

confidence: 99%

Experimental Characterization and Numerical Modelling of Urea Water Solution Spray in High-Temperature Crossflow for Selective Catalytic Reduction Applications

Khan¹,

Bjernemose²,

Lund³

2022

SAE J. STEEP

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“…Studying the solid-liquid transfer dynamics between particles and fluids can deepen the understanding of particle flow heat transfer, aiding in better suspension selection and high-performance liquid cooling design. Previous research mainly focused on particle flow heat transfer [26][27][28][29], ignoring the impact of particle spin motion on flow and temperature fields. With advancements in computer technology, simulating the bidirectional coupling of particle spin motion and fluid flow using numerical methods has become feasible.…”

Section: Introductionmentioning

confidence: 99%

Numerical Simulation Study on Heat Transfer Characteristics of Particle‐Loaded Flow in Microchannels

Song,

Guo,

Wang

et al. 2023

Chem Eng & Technol

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Particle suspension is considered powerful and perspective in enhancing heat transfer, but the unclear nature of particle‐loaded flow limits further understanding of particle suspension. Therefore, in this paper, orthogonal experiments and the arbitrary Lagrangian‐Eulerian method were used to investigate the heat transfer characteristics of particle‐loaded flow. Results indicate that when the particle is at the inlet of the microchannel, the factors arranged in important order are the Reynolds number, blockage ratio, particle initial position, specific heat capacity, and thermal conductivity. When the particle is far from the microchannel inlet, the factors arranged in important order are the Reynolds number, blockage ratio, particle initial position, thermal conductivity, and specific heat capacity.

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“…的增加，芯片的处理能力得到巨大的提升 [1] ．根据摩尔定律，芯片上的晶体管数每 18 个月就会增加一倍 [2] ．高密度的晶体管数也带来了极高密度的热生成，成为了电子元器件进一步集成化和微型化发展的瓶颈之一．这是因为温度的提高会大大降低芯片的工作效率并缩短其使用寿命 [3] ．有研究表明，器件温度在 70~80℃ 时，每增加 1℃其可靠性下降 5%．因此高效热管理技术成为电子元器件进一步发展及高效稳定运行的关键 [4,5] ．微通道液冷由于结构紧凑、易于集成、换热性能优越及安全稳定而具有广泛的应用前景 [6] ．目前的研究主要从微通道构型 [7][8][9][10] 、运行参数 [11,12] 和工作流体 [13][14][15] 等方面来进一步提升热管理性能．在工作流体中，相变胶囊悬浮液由于相变而具有大比热和小温差传热等独特优势而备受关注．相变胶囊悬浮液的流动传热特性直接受颗粒与基液的流动传递作用影响，正如刘淼中等人 [16] 指出那样--颗粒与流体的流固传递在颗粒流中起关键作用．颗粒与流体的流固传递特性研究能加深对颗粒流传热机理的认识，为更好选择悬浮液及设计高性能液冷提供支撑．Hetsroni 等人 [17] 研究了颗粒运动对流动传热的影响，模型仅考虑颗粒的平移运动，结果表明颗粒会改变流场及温度场，颗粒上游传热系数急剧增加．Zahra 等人 [18] 对不同运动状态的单颗粒与流体的对流换热进行了研究，结果表明在颗粒的扰动作用下，流体传热速率得到提升．Liu 等人 [19] 研究了不同比热的粒子对流动传热的影响，发现它们具有不同热力学特性．这些研究主要以颗粒的流动传热为主，忽略了颗粒自旋运动等对流场及温度场的影响．随着数值方法的发展和计算能力的提升，使得考虑颗粒自旋运动的流固双向耦合仿真得以实现．直接考虑颗粒与流体的相互作用而非使用经验或统计模型的直接模拟具有计算精度高，对研究颗粒与流体的流固作用具有重要的意义．这一类的方法主要有有限元任意拉格朗日-欧拉方用离散单元法对颗粒与壁面的相互作用进行了研究，发现颗粒与壁面的相互作用对颗粒的运动具有显著的影响．赵等人 [21] 采用格子玻尔兹曼法研究了颗粒两相流中颗粒对流动的影响，结果表明颗粒的不同流动行为会对流场产生不同的影响．正如崔等人 [22] 为了确保模型的准确性，本文进行了模型验证．采用本文模型方法计算 Zahra 等人 [18]…”

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Numerical simulation of inhibition characteristics of wall temperature rise of phase change microcapsule in liquid-cooled microchannel

Yi-Feng¹,

Wang²,

Li-Si³

et al. 2023

Acta Phys. Sin.

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Phase change microcapsule suspension is a new type of heat-storage and heat-transfer functional fluid. Due to the lack of understanding of flow-solid interaction, there was a difference in understanding the heat transfer performance of suspension fluid. Therefore, the arbitrary Lagrangian-Euler method was used to simulate the flow-solid transfer characteristics of phase-change microcapsules in the liquid-cooled microchannel. Furthermore, the heat-transfer comparison between particle and phase-change capsules was analyzed. And we investigated the influences of the position, shape, and number of capsules on the inhibition of the wall temperature rise. The results show that the wall-temperature-rise inhibition mainly occurs in the upstream area of the capsules. The phase change of capsules can decrease the wall temperature rise. On the other hand, the spin move is faster when the capsules is closer to the wall, and the heat transfer is enhanced. As a result, the inhibition effect on the wall temperature rise becomes stronger, especially close to the heating surface. The circular capsules spin movement is faster and the inhibition performance is better than the ellipse. With the capsules number increase, the wall temperature inhibition effect is also gradually increased.

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Effect of inertial particles with different specific heat capacities on heat transfer in particle-laden turbulent flow

Cited by 6 publications

References 12 publications

Experimental Characterization and Numerical Modelling of Urea Water Solution Spray in High-Temperature Crossflow for Selective Catalytic Reduction Applications

Experimental Characterization and Numerical Modelling of Urea Water Solution Spray in High-Temperature Crossflow for Selective Catalytic Reduction Applications

Numerical Simulation Study on Heat Transfer Characteristics of Particle‐Loaded Flow in Microchannels

Numerical simulation of inhibition characteristics of wall temperature rise of phase change microcapsule in liquid-cooled microchannel

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