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Experimental investigation on the aerodynamics and flow patterns of a 5:1 rectangular cylinder with spoilers 带扰流板的 5:1 矩形气缸的空气动力学和流动模式实验研究
IF 2.8 2区 工程技术 Q2 ENGINEERING, MECHANICAL Pub Date : 2024-08-15 DOI: 10.1016/j.expthermflusci.2024.111284
Shuaihang Lin, Hao Meng, Wenhan Yang, Donglai Gao

The current study experimentally investigates a passive control method for the flow field by placing spoilers symmetrically on the leading edge of a 5:1 rectangular cylinder. The Reynolds number (Re) is based on the inflow velocity and the height of the model. The length of the spoiler is equal to the span length of the model, and the width and angle are defined as w and α. At Re = 1.07 2.50×104, the surface pressure distribution of the model is obtained to initially investigate the effects of α and w on the aerodynamic characteristics. Based on the aerodynamic results, some cases are selected to reveal the control mechanism using the particle image velocimetry (PIV) technique. The proper orthogonal decomposition (POD) is adopted to analyze the POD modes and instantaneous flow. The results show that the spoiler with a certain α can suppress the aerodynamic forces of the model. Spoilers with a relative angle of 247.5° significantly reduce CL by 75 % and slightly reduce CD¯ by 5.5 %. Also, its TKE and RSS values are reduced by 56 % and 57 %, respectively. The PIV visualization shows that the spoiler affects the flow separation at the leading edge. Then, the rolling and interactions of shear layers are suppressed, making them tend to be parallel. Besides, spoilers with a relative angle of 67.5° almost eliminate the flow separation.

本研究通过在 5:1 矩形气缸的前缘对称放置扰流器,对流场的被动控制方法进行了实验研究。雷诺数(Re)基于流入速度和模型高度。扰流板的长度等于模型的跨度,宽度和角度定义为 w 和 α。在 Re = 1.07 2.50×104 时,得到了模型的表面压力分布,以初步研究 α 和 w 对气动特性的影响。在气动结果的基础上,利用粒子图像测速(PIV)技术,选择一些情况来揭示控制机制。采用适当的正交分解(POD)来分析 POD 模式和瞬时流。结果表明,具有一定 α 的扰流板可以抑制模型的空气动力。相对角为 247.5°的扰流板可显著降低 75% 的 CL′,并略微降低 5.5% 的 CD¯。此外,其 TKE 和 RSS 值也分别降低了 56 % 和 57 %。PIV 可视化结果显示,扰流板影响了前缘的气流分离。然后,剪切层的滚动和相互作用被抑制,使其趋于平行。此外,相对角度为 67.5° 的扰流板几乎消除了流动分离。
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引用次数: 0
Laminar flow and convective heat transfer of ferrofluid in a tube under oscillating magnetic fields: Effect of magnetic phase shift 摆动磁场下铁氟龙流体在管内的层流和对流传热:磁相移的影响
IF 2.8 2区 工程技术 Q2 ENGINEERING, MECHANICAL Pub Date : 2024-08-14 DOI: 10.1016/j.expthermflusci.2024.111293
Esra Yagci, Oguz Kaan Yagci, Tulin Bali, Orhan Aydin

In this study, laminar flow and forced convective heat transfer of water-based ferrofluids flowing through a uniformly heated pipe are experimentally investigated under the presence of phase-shifted oscillating magnetic fields. To investigate the effect of phase shift on heat transfer, electromagnets are positioned along the tube, and oscillating magnetic fields are applied with various phase shift angles between opposing magnetic poles. Experiments are conducted for different Reynolds numbers (400 to 1000), magnetic field frequencies (0 Hz, 1 Hz, and 5 Hz), phase shift angles (0°, 90°, and 180°), and nanoparticle volume fractions (0.5 % and 1 %). For each parameter set, local and average Nusselt numbers, as well as pressure drop values, are determined, and the effect of applied magnetic fields on the heat transfer rate is extensively discussed. Results showed that, applying an external magnetic field resulted in significant enhancements in the forced convective heat transfer of ferrofluid. Under an oscillating magnetic field with 0° phase shift, maximum of 40 % and 20.6 % enhancements were observed in local and average Nusselt numbers respectively under the investigated parameters. Furthermore, applying oscillating magnetic fields with a phase shift between opposing poles caused significant fluctuations in the fluid, led to remarkable improvements in convective heat transfer rates. For 90° and 180° phase shifts, enhancements in local and average Nusselt numbers were observed to increase up to 73 % and 36 %, respectively.

本研究对流经均匀加热管道的水基铁流体在相移振荡磁场作用下的层流和强制对流传热进行了实验研究。为研究相移对传热的影响,沿管道放置电磁铁,并在相对磁极之间施加不同相移角的振荡磁场。实验针对不同的雷诺数(400 至 1000)、磁场频率(0 Hz、1 Hz 和 5 Hz)、相移角度(0°、90° 和 180°)以及纳米粒子体积分数(0.5 % 和 1 %)进行。针对每组参数,确定了局部和平均努塞尔特数以及压降值,并广泛讨论了外加磁场对传热速率的影响。结果表明,外加磁场显著提高了铁流体的强制对流传热。在相移为 0° 的振荡磁场下,根据所研究的参数,局部努塞尔特数和平均努塞尔特数分别提高了 40% 和 20.6%。此外,在对立磁极之间施加相移的振荡磁场会在流体中引起显著波动,从而显著提高对流传热率。在相移 90° 和 180° 时,观察到局部和平均努塞尔特数分别增加了 73% 和 36%。
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引用次数: 0
Sub-regimes of horizontal gas–liquid intermittent flow: State-of-the-art and future challenges 水平气-液间歇流动的次制度:最新技术和未来挑战
IF 2.8 2区 工程技术 Q2 ENGINEERING, MECHANICAL Pub Date : 2024-08-14 DOI: 10.1016/j.expthermflusci.2024.111281
Abderraouf Arabi , Youcef Zenati , Jack Legrand , El-Khider Si-Ahmed

Based on the shape of the interface elongated bubble/liquid slugs and the liquid slugs’ aeration, the horizontal intermittent flow can be divided into three sub-regimes including plug (PG), Less Aerated Slug (LAS) and Highly Aerated Slug (HAS) flows. These flow sub-regimes were observed from experiments performed using air–water mixture and small pipe diameters. This paper presents an analysis of the results obtained with the aim of constituting the state-of-the-art of this sub-regimes classification.

The critical review, of the current state of knowledge, has led to the conclusion that the subdivision of intermittent flow into sub-regimes may provide a better means of apprehending, understanding and advancing in the modelling of slug parameters, Interfacial Area Concentration, Pipeline Integrity Management, intermittent flow behavior across singularities, as well as for the development of more realistic mechanistic models. The acquired knowledge can be beneficial for petroleum and gas, nuclear and chemical engineering industries among others.

Finally, based on the presented state-of-the art, some recommendations are given for future works using this approach. These reflection paths will allow improving our comprehension on intermittent flow, promoting the development of more robust models.

根据细长气泡/液态蛞蝓界面的形状和液态蛞蝓的曝气情况,水平间歇流可分为三种子形态,包括塞流(PG)、少曝气蛞蝓流(LAS)和高曝气蛞蝓流(HAS)。这些流动亚状态是在使用空气-水混合物和小管径进行的实验中观察到的。本文对所获得的结果进行了分析,目的是对这一子规程分类的最新进展进行总结。通过对当前知识水平的批判性回顾,我们得出结论:将间歇流细分为子规程,可以更好地理解、认识和推进弹头参数建模、界面区浓度、管道完整性管理、跨越奇点的间歇流行为,以及开发更逼真的力学模型。所获得的知识可用于石油和天然气、核能和化学工程等行业。最后,根据所介绍的最新技术,为今后使用这种方法开展工作提出了一些建议。这些反射路径将有助于提高我们对间歇流的理解,促进开发更强大的模型。
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引用次数: 0
Aerodynamic performances and near wake of an Ahmed body under unsteady flow conditions 非稳定流条件下艾哈迈德体的气动性能和近尾流
IF 2.8 2区 工程技术 Q2 ENGINEERING, MECHANICAL Pub Date : 2024-08-13 DOI: 10.1016/j.expthermflusci.2024.111285
Giorgio Moscato, Giovanni Paolo Romano

This paper experimentally characterizes unsteady effects and flow fields around the Ahmed Body, by analyzing global forces and detailed wake effects. The results are compared to those obtained under steady conditions, with varying wind tunnel velocities and different yaw angles between the model and the free stream. Unsteady fields are generated by means of oscillating blades positioned at the inlet of the test section, whose amplitudes and frequencies can be easily controlled. Specifically, low frequencies, around a few Hertz, as those in the typical range generating load oscillations on vehicles, are considered. The results in terms of force coefficients, obtained by a dynamometric balance, and velocity fields, obtained by Particle Image Velocimetry, are processed in order to derive time-average statistics and also phase-average statistics, as related to forcing blade instantaneous positioning. This type of analysis can be performed thanks to the high temporal resolution of measurement systems, around 100 Hz for the force measurements and around 4000 Hz for the velocity measurements. Results in steady conditions well compare with previous results in references, both as functions of wind tunnel velocity and yaw angles. In unsteady conditions, whatever amplitude is considered, time-average drag and lift coefficients and their dependence on yaw angle are consistently lower compared to the steady case. Phase-averaged coefficients in unsteady conditions can oscillate by around 20 % in comparison to time-average values and these fluctuations are strongly dependent on yaw angle and amplitude of oscillations, thus suggesting that they both contribute to instantaneous loads. Present investigations are related to improvements in set-up of control systems in assisted-driving (self-driving) vehicles.

本文通过分析全局力和详细的尾流效应,对艾哈迈德体周围的非稳态效应和流场进行了实验描述。实验结果与稳定条件下获得的结果进行了比较,风洞速度不同,模型与自由流之间的偏航角也不同。非稳态场是通过位于试验段入口处的振荡叶片产生的,其振幅和频率很容易控制。具体来说,考虑的是低频,约为几赫兹,这是在车辆上产生负载振荡的典型范围。通过对测力平衡获得的力系数结果和粒子图像测速仪获得的速度场结果进行处理,以得出时间平均统计量和相位平均统计量,这与强制叶片的瞬时定位有关。由于测量系统的时间分辨率很高,力测量的时间分辨率约为 100 Hz,速度测量的时间分辨率约为 4000 Hz,因此可以进行此类分析。作为风洞速度和偏航角的函数,稳定条件下的结果与之前参考文献中的结果进行了很好的比较。在非稳态条件下,无论考虑何种振幅,时间平均阻力和升力系数及其与偏航角的关系都低于稳态情况。与时间平均值相比,非稳态条件下的相位平均系数可波动约 20%,这些波动与偏航角和振幅密切相关,因此表明它们都对瞬时载荷有影响。目前的研究与辅助驾驶(自动驾驶)车辆控制系统设置的改进有关。
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引用次数: 0
Collision adhesion law of oil Droplets-Bubbles with different particle sizes in free floating 自由漂浮的不同粒径油滴-气泡的碰撞粘附定律
IF 2.8 2区 工程技术 Q2 ENGINEERING, MECHANICAL Pub Date : 2024-08-13 DOI: 10.1016/j.expthermflusci.2024.111292
Jiangyun Wang , Zhuang Wang , Xinfeng Zhai , Jiaqi Li , Lin Guo , Quan Xu

The treatment of oily wastewater has become a serious problem in the late stage of oilfield development. At the same time, it is of great significance to the improvement of ecological environment. As the key process of oil-bearing wastewater treatment, the study on the binding and adhesion law of oil droplets and bubbles in flotation and its related mechanism can provide reference for its application. Using a double high-speed camera acquisition system, the floating process and collision adhesion law of oil droplets and bubbles in a vertical transparent circular tube were experimentally studied, and the collision adhesion process of oil droplets (0.721 ∼ 3.759 mm) and bubbles (0.797 ∼ 2.886 mm) in different diameters were analysed. It is concluded that the oil droplet and the bubble collide with each other, and then the bubble slides along the surface of the oil droplet, and a neck shape appears at the end of the contact site, and then the neck increases with the diffusion of the oil droplet to form an oil-bubble adhesion body. And the process of elastic drags and contraction separation of the mixture is also demonstrated. It is found that the combination of oil droplets and bubbles with different diameters will have two types of collision adhesion modes, which oil droplet type and oil film type, respectively. Therefore, the diameter ratio of oil droplets and bubbles is a key factor, and when the diameter ratio is greater than 0.75, the adhesion mode of the adhesive body changes from unstable oil droplet type to more stable oil film type.

含油废水的处理已成为油田开发后期的一个严重问题。同时,对改善生态环境也具有重要意义。作为含油污水处理的关键工序,研究油滴和气泡在气浮过程中的结合、粘附规律及其相关机理,可为其应用提供参考。利用双高速摄像采集系统,实验研究了油滴和气泡在垂直透明圆管中的上浮过程和碰撞粘附规律,分析了不同直径油滴(0.721 ∼ 3.759 mm)和气泡(0.797 ∼ 2.886 mm)的碰撞粘附过程。结论是油滴与气泡碰撞后,气泡沿油滴表面滑动,在接触部位的末端出现颈部形状,然后颈部随着油滴的扩散而增大,形成油泡粘附体。同时还展示了混合物的弹性拖曳和收缩分离过程。研究发现,不同直径的油滴和气泡组合会产生两种碰撞粘附模式,分别是油滴型和油膜型。因此,油滴和气泡的直径比是一个关键因素,当直径比大于 0.75 时,粘合体的粘合模式将从不稳定的油滴型转变为更稳定的油膜型。
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引用次数: 0
Flow mixing enhancement by crossflow induced oscillations of an open semicircular cylinder 开放式半圆形圆筒的横流诱导振荡加强了流动混合
IF 2.8 2区 工程技术 Q2 ENGINEERING, MECHANICAL Pub Date : 2024-08-08 DOI: 10.1016/j.expthermflusci.2024.111283
A. Barrero-Gil

Flow-induced vibrations of a rigid prism with an open semicircular cross section, supported elastically, were experimentally studied in a free-surface water channel. The objective of the study was to explore the prism’s potential to promote flow mixing in its wake and simultaneously harvest mechanical energy from the incoming flow. The mechanical dimensionless parameters, namely the mass ratio and damping, were kept constant, focusing primarily on the influence of flow speed (or reduced velocity U) on mixing efficiency and energy extraction. The following findings were obtained: (i) a clear correlation exists between the efficiency of mixing and the efficiency of energy extraction, (ii) mixing efficiency is higher in the near wake and gradually decreases downstream, and (iii) mixing efficiency scales with A(f/U)2, where A and f represent the dimensionless amplitude and frequency of the prism’s oscillation, respectively. This indicates that flow mixing is directly influenced by the transverse acceleration of the prism and the unperturbed flow speed. Then, maximum mixing efficiency is expected to be achieved when high oscillation amplitudes occur at low reduced velocities which suggest that synchronization of vortex shedding contributes to enhance flow mixing.

我们在自由水面水道中对弹性支撑的半圆形截面刚性棱柱的流动诱导振动进行了实验研究。研究的目的是探索棱柱在其尾流中促进水流混合的潜力,同时从流入的水流中获取机械能。机械无量纲参数(即质量比和阻尼)保持不变,主要关注流速(或减速度 U∗)对混合效率和能量提取的影响。研究结果如下:(i) 混合效率和能量萃取效率之间存在明显的相关性;(ii) 混合效率在近尾流处较高,在下游逐渐降低;(iii) 混合效率与 A∗(f∗/U∗)2(其中 A∗ 和 f∗ 分别代表棱镜振荡的无量纲振幅和频率)成比例关系。这表明,流动混合直接受棱镜横向加速度和无扰动流速的影响。因此,当低流速下出现高振荡幅度时,混合效率有望达到最大,这表明涡流脱落的同步化有助于加强流动混合。
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引用次数: 0
Data-informed characterization of spatio-temporal scales in experiments of microconfined high-pressure transcritical turbulence 微封闭高压跨临界湍流实验时空尺度的数据信息表征
IF 2.8 2区 工程技术 Q2 ENGINEERING, MECHANICAL Pub Date : 2024-08-08 DOI: 10.1016/j.expthermflusci.2024.111282
Enrique Hurtán , Carlos Monteiro , Marc Jofre , Jasmina Casals-Terré , Lluís Jofre

The spatio-temporal scales of microconfined high-pressure transcritical turbulence are characterized in relation to the resolution capabilities of present time-resolved two-dimensional μPIV technology. Utilizing CO2 as the working fluid, the physical scales are examined by considering the main dimensionless groups of the problem, which correspond to the Reynolds, Brinkman, and Stokes numbers and the mass fraction of particles in the fluid. In detail, the methodology employed leverages direct numerical simulation data to inform the estimation of hydrodynamic, thermophysical, and particle-related scales, and selects a state-of-the-art μPIV setup to describe the optical performance of the current technology. The results indicate that the temporal scales can be experimentally captured for a wide range of operating conditions. However, the scenario becomes much more complex when trying to capture the spatial scales of microconfined high-pressure transcritical turbulent flow. Particularly, the Kolmogorov and Batchelor spatial scales can be captured for bulk Reynolds numbers below O(103). Otherwise, the spatial scales can only be partially captured and/or remain completely masked due to insufficient resolution, like for example in the case of boundary layer viscous scales and fluid density variations. This limitation is not imposed by the tracer behavior of microparticles, as the Stokes number remains significantly low for all the system configurations studied. Instead, the limitation is mainly a result of the optical capabilities of present μPIV systems. Finally, given the generalizable properties of dimensionless numbers, the results and insight obtained can be extended to other experiments of μPIV-based visualization/quantification of microconfined multiscale flows involving large thermophysical variations.

根据目前时间分辨二维 μPIV 技术的分辨率能力,对微封闭高压跨临界湍流的时空尺度进行了描述。利用二氧化碳作为工作流体,通过考虑问题的主要无量纲组(对应于雷诺数、布林克曼数和斯托克斯数以及流体中颗粒的质量分数)来研究物理尺度。具体而言,所采用的方法利用直接数值模拟数据来估算流体力学、热物理和颗粒相关尺度,并选择最先进的 μPIV 设置来描述当前技术的光学性能。结果表明,可以通过实验捕捉到各种运行条件下的时间尺度。然而,当试图捕捉微封闭高压跨临界湍流的空间尺度时,情况就变得复杂得多。特别是在体积雷诺数低于 O(103) 时,可以捕捉到 Kolmogorov 和 Batchelor 空间尺度。否则,由于分辨率不足,空间尺度只能被部分捕捉和/或完全掩盖,例如边界层粘性尺度和流体密度变化。微颗粒的示踪行为并没有造成这种限制,因为在所研究的所有系统配置中,斯托克斯数都很低。相反,这种限制主要是由目前 μPIV 系统的光学能力造成的。最后,考虑到无量纲数的通用特性,所获得的结果和见解可扩展到其他基于 μPIV 的涉及大量热物理变化的微约束多尺度流动的可视化/量化实验。
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引用次数: 0
Corrigendum to “Effect of liquid preheating on high-velocity airblast atomization: From water to crude rapeseed oil” [Exp. Therm. Fluid Sci. 102 (2019) 137–151] 液体预热对高速喷气雾化的影响:从水到粗菜籽油" [Exp. Therm. Fluid Sci. 102 (2019) 137-151] 的更正
IF 2.8 2区 工程技术 Q2 ENGINEERING, MECHANICAL Pub Date : 2024-08-05 DOI: 10.1016/j.expthermflusci.2024.111275
András Urbán , Milan Malý , Viktor Józsa , Jan Jedelský
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引用次数: 0
Experimental evaluation of the flow field induced by an active vortex generator 主动涡流发生器诱导流场的实验评估
IF 2.8 2区 工程技术 Q2 ENGINEERING, MECHANICAL Pub Date : 2024-08-05 DOI: 10.1016/j.expthermflusci.2024.111280
Sen Wang, Bryce Horn, Findlay McCormick, Sina Ghaemi

This investigation examined the flow field generated by a ramp-shaped vortex generator (VG) that underwent active oscillation within a laminar boundary layer. The oscillations were applied through a servomotor, which pivoted the VG around its leading edge. The study evaluated the influence of varying the maximum VG height during the oscillations (h), actuation frequency (f), and the waveform governing the periodic oscillation of the VG. Planar particle image velocimetry (PIV) measurements were conducted to estimate flow mixing and the drag induced by the VG. The height-based Reynolds number (Reh) ranged from 300 to 600, and the chord-based Strouhal number (Stc) for the oscillations varied from 0.67 to 3.33. The findings of the study indicate that active VGs lead to a greater wall-normal transport of streamwise momentum and result in lower drag compared to static VGs. Furthermore, increasing h results in larger momentum transport and drag of the active VGs. The investigation also revealed that the highest momentum transport and drag occurred when f was close to the instability frequency of the shear layer. The results show the potential of active VGs for separation control under various flow conditions.

这项研究考察了在层流边界层内进行主动振荡的斜坡形涡流发生器(VG)所产生的流场。振荡是通过伺服电机施加的,伺服电机使 VG 绕其前缘旋转。研究评估了改变振荡期间 VG 最大高度(h)、驱动频率(f)和 VG 周期性振荡波形的影响。进行了平面颗粒图像测速仪(PIV)测量,以估算流体混合和 VG 诱导的阻力。基于高度的雷诺数(Reh)从 300 到 600 不等,基于弦线的斯特劳哈尔数(Stc)从 0.67 到 3.33 不等。研究结果表明,与静态 VG 相比,主动 VG 会导致更大的流向动量的壁面法向传输,并导致更低的阻力。此外,增加 h 会导致主动 VG 的动量传输和阻力增大。研究还发现,当 f 接近剪切层的不稳定频率时,动量传输和阻力最大。研究结果表明,在各种流动条件下,主动 VG 都具有进行分离控制的潜力。
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引用次数: 0
Study on the microscopic characteristics of pentanol/highly active fuel spray based on high-speed droplet tracking velocimetry technology 基于高速液滴跟踪测速技术的戊醇/高活性燃料喷雾微观特性研究
IF 2.8 2区 工程技术 Q2 ENGINEERING, MECHANICAL Pub Date : 2024-08-04 DOI: 10.1016/j.expthermflusci.2024.111279
Sicheng Lai , Wenjun Zhong , Zhaochen Jiang , Tamilselvan Pachiannan , Wenjun Wang , Chong Wang , Liang Zhang , Zhixia He

Pentanol blending with highly reactive fuels for internal combustion engines holds considerable promise. The atomization of sprays closely influences the efficiency and combustion characteristics of the system. Based on Particle Tracking Velocimetry and high-speed shadow imaging technology, we propose a method termed High-speed Droplet Tracking Velocimetry for analyzing spray particle size. Prior to conducting our study, we validated the reliability of High-speed Droplet Tracking Velocimetry through comparisons with the Malvern and Phase Doppler methods. This study utilized long working distance micro high-speed shadow imaging technology in a visualized constant volume combustion chamber to investigate the spray micro-characteristics of pentanol blended with highly reactive fuels, including Fatty Acid Methyl Ester, Hydrogenated Catalytic Biodiesel, and Diesel. The results indicate that under all operating conditions, the droplets of P20H80 (the volume fraction of 20 % n-pentanol mixed with 80 % Hydrogenated Catalytic Biodiesel) are smaller and more uniformly distributed, demonstrating the minimum Sauter Mean Diameter, characteristic diameter, and width of droplet size distribution. The droplet velocities of P20H80 are the lowest, followed by P20Di80 (the volume fraction of 20 % n-pentanol mixed with 80 % Diesel), and P20B80 (the volume fraction of 20 % n-pentanol mixed with 80 % Fatty Acid Methyl Ester) exhibits the highest velocities. These velocity differences among the three fuels generally remain within 10 %-20 % across various injection pressures. P20Di80 shows the highest Reynolds and Weber numbers, followed by P20H80, with P20B80 having the smallest values due to its intermediate physical properties. The gaps between each fuel type range from 20 % to 30 %.

将戊醇与高活性燃料混合后用于内燃机大有可为。喷雾的雾化程度密切影响着系统的效率和燃烧特性。基于粒子跟踪测速仪和高速阴影成像技术,我们提出了一种用于分析喷雾粒度的方法,称为高速液滴跟踪测速仪。在进行研究之前,我们通过与马尔文法和相位多普勒法进行比较,验证了高速液滴跟踪测速仪的可靠性。本研究利用可视化恒容燃烧室中的长工作距离微高速阴影成像技术,研究了戊醇与脂肪酸甲酯、氢化催化生物柴油和柴油等高活性燃料混合后的喷雾微特征。结果表明,在所有操作条件下,P20H80(体积分数为 20% 的正戊醇与 80% 的加氢催化生物柴油混合)的液滴更小,分布更均匀,显示出最小的萨特平均直径、特征直径和液滴尺寸分布宽度。P20H80 的液滴速度最低,其次是 P20Di80(体积分数为 20% 的正戊醇与 80% 的柴油混合),而 P20B80(体积分数为 20% 的正戊醇与 80% 的脂肪酸甲酯混合)的速度最高。在不同的喷射压力下,三种燃料的速度差异一般保持在 10%-20% 之间。P20Di80 显示出最高的雷诺数和韦伯数,其次是 P20H80,而 P20B80 由于其中等物理性质而显示出最小值。每种燃料之间的差距在 20% 到 30% 之间。
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引用次数: 0
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Experimental Thermal and Fluid Science
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