红外热成像方法测量火旋风温度的实验研究

应用热成像方法获得了火旋风特有的物理现象，火焰的大高度直径比；并将细水雾作用于火旋风和油池火实验；相同的雾通量作用下，火旋风能被熄灭，油池火却不能被灭掉。由此而对细水雾作用于火旋风的机理进行了讨论，对于不同物理形态的火焰，细水雾灭火的有效性不同。并对细水雾抑制熄灭火旋风火灾机理的研究提出了一种有效的实验方法。     

细水雾抑制气体火焰的实验测量

运用APV(Adaptive Phase／Doppler Velocimeter)系统、红外热成像方法和热电偶测温方法对细水雾和气体扩散火焰的作用过程中雾通量等雾场特性做了有效的测量，研究了细水雾和气体扩散火焰的作用过程。探索细水雾抑制扩散火焰的机理和规律。采用一种可以分离出细水雾灭火时不同机理相对贡献的实验方法，得到了比较理想的结论，用实验数据形象定量的表征出了在细水雾灭火时，水雾的蒸发潜热吸热作用、热容吸热作用以及稀释氧气作用对抑制气体扩散火焰所起的相对贡献。在实验条件下，讨论了细水雾各种灭火机理，合理解释了实验中出现的一些现象。实验研究表明，细水雾的各种灭火机理对于抑制火焰所发挥的作用不同，这对于细水雾灭火技术的发展很有意义。     

细水雾与火焰相互作用的红外全场诊断方法研究

利用ＴＶＳ－２０００ＳＴ型热像系统,通过观察和测量细水雾与火焰相互作用前后火焰热场结构的变化,分别对细火雾与煤油、酒精和正庚烷等液体扩散火焰的相互作用进行了实验研究,为进一步认识细水雾与扩散火焰相互作用的机理提供了简捷可靠的实验手段     

三维LDV/APV系统研究细水雾与射流卷吸现象

利用三维激光多普勒测速计和自适性相位多普勒速度计系统（三维ＬＤＶ／ＡＰＶ系统）,通过观察和测量劝水雾被射流卷吸的现象,获取了细水雾的平均速度、平均粒径和雾通量等特性参数,深化认识细水雾被射流卷吸的机理,为下一步进行细水雾被火焰卷吸现象的实验研究打下了良好的基础。     

细水雾发生及抑制液体火焰的实验研究

本文设计加工了细水雾发生器，并且应用三维LDV／APV(Adaptive Phase/Doppler Velocimeter)系统对其产生的细水雾雾场特性参数做了有效的测量，并在此基础上进行了细水雾抑制液体火有效性的模拟实验．利用热像仪、热电偶和摄像机等仪器研究了这种细水雾抑制熄灭煤油火和酒精火的过程。实验结果表明细水雾技术具有应用在灭火系统上的可行性，并具有优越的特点。     

细水雾与固体木垛火相互作用的红外热像研究

利用TVS－2000ST型热系统,以热电偶为辅助观察和测量细水雾与火焰相互作用前后火焰热场的结构的变化,分别对细水雾与不同尺寸和功率的固体木火的相相作用进行了实验研究,为进一步认识细水雾与固体扩散火焰相互作用的机理提供了简捷可靠的实验手段。     

细水雾测量中APV的光路布局

结合细水雾的特点和粒子的光散射理论 ,通过模拟计算和实验研究 ,对APV (AdaptivePhase DopplerVelocimeter)光路系统设计了合适的参数 ,并进行了合理布局。对细水雾雾场中粒子的特性参数进行了实验测量研究 ,对细水雾雾场的速度分布、滴径分布以及雾通量的测量等都得到了合理的实验结果。     

细水雾与火焰相互作用的热成像全场动态测量

利用ＴＶＳ－２０００ＳＴ热像系统对细水雾与火焰相互作用过程中的动态热场进行了测试,获取了细水雾作用前后火焰热场信息变化的时空分布,从而为进一步深化认识细水雾与火焰相互作用的机理提供了简捷可靠的实验手段。同时,对在不同水压下细水雾与火焰相互作用的全过程进行了动态测试。     

细水雾与射流卷吸现象的LDV/APV测量研究

本文利用三维激光多普勒测 计和自适性相位移普勒速度计系统（三维ＬＤＶ／ＡＰＶ系统）,通过观察和测量细水雾被射郑吸的现象,获取了细水雾的平均速度,平均粒径和雾能量等特性参数,深化认识细水雾被射流卷吸的机理,为下一步进行细水雾被火焰卷吸现象的实验研究打下了良好的基础。     

基于统计窄谱带模型的油料火焰辐射光谱模拟

近年来油料火灾污染事故频发危害性极大,通过分析光谱特性来提取火灾信息已成为研究油料火灾事故的重要途径.目前国内外学者已建立了多种气体辐射和炭黑辐射的模型对燃料燃烧进行研究,但少有对火焰光谱进行建模深入分析燃烧污染产物光谱特征信息.本文搭建了油料火焰光谱测试平台,测量了单一尺度下酒精、92号汽油、95号汽油和0号柴油的火...     

Dynamics of a liquid plug in a capillary duct powered by vapor explosion

A theoretical model of liquid plug dynamics powered by vapor explosion in a capillary duct has been proposed in order to provide guidance for designing a fluid propulsion device. The model can evaluate performance parameters such as the amount of useful work, efficiency of energy conversion, generated vapor volume and displacement volume rate of liquid. For example, the efficiency of energy conversion for water under atmospheric pressure and room temperature is calculated at 2.8%. The prediction of the vapor volume agrees well with existing experimental result. The prediction of the displacement volume rate also agrees well with the experimental result and suggests the existence of optimum heat flux at which the displacement volume rate is maximum.     

应用于LED肋片散热的均温板效果实验研究

将紫铜板和不同尺寸的均温板作为均温组件,布置在LED模拟热源与肋片之间,研究它们在不同热流密度下的均温及热阻表现。实验结果表明,紫铜板和均温板都可使肋片底面温差显著下降,但均温板具有更短的启动时间。只有当热流密度超过一定值时,均温板的均温性能才会明显优于紫铜板,同时均温板尺寸对其均温性能有很大的影响。随着热流密度的增大,紫铜板热阻几乎不变,均温板热阻逐渐减小并趋于平缓；大尺寸均温板在获得小温差的同时,热阻也最小。     

High‐Efficiency Low‐Resistance Oil‐Mist Coalescence Filtration Using Fibrous Filters with Thickness‐Direction Asymmetric Wettability

Conventional aerosol filters typically have homogeneous wettability with limited filtration ability especially for small oil mists. Increasing filtration efficiency using thicker filter pad or finer fibers both result in considerable increase of pressure drop, which adversely increases energy consumption. It remains a challenge to develop effective filter materials that can effectively remove oil mists from air at a low flow resistance. Here, a novel concept about improving oil mist filtration efficiency without apparently increasing pressure drop using a fibrous filter with asymmetric wettability across the thickness is demonstrated. Dip‐coating and single‐side electrospraying are used to make fibrous filter have a homogeneous superoleophobicity or directional oil‐transport function. When the two are combined together, they show a filtration efficiency as high as 99.45% for small oil mists (size 0.01–0.8 µm) and nearly 100% for large oil mists (size 0.5–20 µm) with a pressure drop of 9.29 kPa. With the same thickness and fibrous structure, our directional oil‐transport/superoleophobic filter has higher quality factor than those with homogeneous oleophilic, superoleophobic, and asymmetric wettability of other superoleophilic/superoleophobic combinations, for both small and large oil mists. Directional oil transport‐superoleophobic filters may lead to a novel, high‐performance, low energy consumption oil mist separation technology.     

激光多普勒细水雾雾场特性实验研究

结合细水雾的特点和粒子的光散射理论,对三维APV(adaptivephase/Dopplervelocimeter)的光路系统设计了合适的参数,并进行了合理地布局。对细水雾雾场进行了实验研究,细水雾的速度分布、滴径分布以及雾通量的测量等都得到了合理的实验结果。     

Pool Boiling Experiments on a Nano-Structured Surface

The effect of nano-structured surfaces on pool boiling was investigated. Saturated and subcooled pool boiling experiments were performed on a horizontal heater surface coated with vertically aligned multiwalled carbon nanotubes (MWCNTs). MWCNTs were synthesized using the chemical vapor deposition (CVD) process. In this paper, MWCNT forests of two distinctly different heights (Type A: 9-$mu$m height, and Type B: 25-$mu$ m height) were synthesized separately on silicon wafers. PF-5060 was used as the test liquid. The results show that Type-B MWCNTs yield distinctly higher heat fluxes under subcooled and saturated conditions for both nucleate and film boiling. Type-A MWCNTs provide similar enhancement in nucleate boiling (as Type-B) for both saturated and subcooled conditions. Type-B MWCNTs enhanced critical heat flux (CHF) by 40%. Increasing the height of the MWCNTs is also found to extend the wall super heat required for CHF. In contrast, Type-A MWCNTs provide only marginal enhancement in film boiling compared to bare silicon wafer, for both saturated and subcooled film boiling. Type-B MWCNTs enhanced the heat flux in the film boiling regime for the Leidenfrost point by 175% (compared to bare silicon wafer).