飞机除冰/防冰液的流变特性研究

使用Brookfield粘度计对非牛顿流体型飞机除冰/防冰液的流变性进行了研究,通过对飞机除冰/防冰液剪切速率和剪切应力的测量和数据拟合,发现在中等剪切速率条件下,飞机除冰/防冰液符合幂律流体的流变特性;在剪切率趋近于0和趋近于无穷大时,飞机除冰/防冰液的粘度都是趋近于一个固定值,据此推导出新的流变方程,新流变方程能在整个剪切速率范围内很好的反应飞机除冰/防冰液的流变特性。     

飞机除冰/防冰液的流变特性研究

使用Brookfield粘度计对非牛顿流体型飞机除冰/防冰液的流变性进行了研究,通过对飞机除冰/防冰液剪切速率和剪切应力的测量和数据拟合,发现在中等剪切速率条件下,飞机除冰/防冰液符合幂律流体的流变特性;在剪切率趋近于0和趋近于无穷大时,飞机除冰/防冰液的粘度都是趋近于一个固定值,据此推导出新的流变方程,新流变方程能在整个剪切速率范围内很好的反应飞机除冰/防冰液的流变特性。     

非牛顿型飞机除冰/防冰液增稠体系及增稠机理研究

通过对比不同种类增稠剂的性能,按照非牛顿型飞机除冰/防冰液对黏度的特殊要求,筛选出可用于非牛顿型飞机除冰/防冰液增稠的增稠体系。采用Brookfield DV型旋转黏度计测定多种飞机除冰/防冰液剪切后的黏度,分析不同增稠体系的除冰/防冰液经不同程度剪切后的黏度变化趋势以及不同增稠体系的除冰/防冰液的增稠机理,结合目前民用航空市场上各种非牛顿型飞机除冰/防冰液的调研情况,综合评价了最适合用于飞机除冰/防冰液增稠体系的增稠剂。     

评估飞机除冰/防冰液产生凝胶数量的方法研究

按照标准搭建了飞机除冰防冰液国际通行标准中评估飞机除冰防冰液(Ⅱ/Ⅳ型)产生凝胶性能的三种评估方法,即连续干燥水合试验方法、冷储存稳定性试验方法和薄膜稳定性试验方法,并对目前国际和国内已有的Ⅱ/Ⅳ型除冰液进行试验验证。     

介质阻挡放电等离子体防除冰实验研究

在无风环境下分别进行了交流介质阻挡放电（AC-DBD）、纳秒脉冲介质阻挡放电（NS-DBD）及射频介质阻挡放电（RF-DBD）等离子体除冰实验研究,采用高速成像技术与红外测温成像技术分别记录除冰过程中介质层表面相变及温度动态变化过程,对比分析了三者的优缺点及传热机理。结果表明,在功率相同的条件下,AC-DBD等离子体激励的温升迅速,加热范围广,除冰实验效果最佳;对于NS-DBD等离子体激励,低压高频的除冰性能明显优于高压低频;RF-DBD等离子体激励放电主要集中在电极条边缘,放电剧烈,但电极间的区域温度较低,导致整体除冰效果不佳。最后,选择除冰效果最好的AC-DBD等离子体激励,在结冰风洞中进行了防冰实验研究。结果表明,AC-DBD等离子体激励整体防冰效果较好,但在防冰过程中,前缘会出现局部结冰,需进一步优化激励器构型及能量,提高AC-DBD等离子体激励防冰效果。     

非牛顿型飞机除冰/防冰液黏度影响因素分析

飞机除冰/防冰液是一种重要的航空化学品,其中非牛顿型飞机除冰/防冰液黏度是其一项关键理化指标。黏度的大小直接影响到其防冰性能和空气动力学性能,对飞机运行安全有着直接的影响。通过对非牛顿型飞机除冰/防冰液在不同温度、不同转速、不同浓度、不同静置时间条件下的黏度进行测试,并对结果进行了分析及曲线拟合研究。结果表明,非牛顿型飞机除冰/防冰液具有剪切变稀且难以恢复的特性,同时黏度对温度、浓度、转速等因素具有很大的敏感性,并给出了黏度对温度和转速影响因素的拟合曲线。     

低表面能涂层在飞机防除冰领域的研究进展与应用

阐述了飞机防除冰的重要性及通常采用的防除冰方法,简要介绍了疏水型低表面能涂层在飞机防除冰领域的辅助作用及该类涂层的疏水机理和分类,评述了几类含氟低表面能树脂在疏水涂料领域的研究进展以及该类涂层在飞机蒙皮和防除冰领域的应用。     

机场道面除冰剂除冰性能测试方法

介绍了评估机场道面除冰剂除冰性能的三种试验方法,即冰融化试验、冰削弱试验和冰穿透试验,并且按照SAE AIR 6170、SAE AIR 6172和SAE AIR 6211的要求进行了相关试验。     

基于低表面能弹性聚氨酯体系制备防除冰涂料的可行性研究

提出了基于低表面能弹性聚氨酯体系制备防除冰涂料的可行性。对所试制的涂层在大型结冰风洞中进行了防除冰效果的测试。通过与国内同类产品的对比，防除冰效果较好。从涂层的冰黏附特性和工艺参数优化研究、树脂分子结构的设计及合成工艺研究、树脂弹性的调控以及优化研究、涂层表面状态与表面能的调控及优化研究、结冰风洞验证等方面重点论证了研究方案的可行性。     

电网架空地线用自吸热防覆冰易除冰涂料的研制

为保障南方山区冬季高湿冻雨恶劣环境下的输电线路安全,在充分调研现有各种主动被动防冰方法和技术的基础上,开展了新型长效防覆冰易除冰涂层组分/结构优化工作.通过着冰力、接触角、人工老化、附着力等量化指标,探索建立了涂层防覆冰易除冰长效服役寿命加速评价方法,并在宁波电网架空地线中实现示范应用.     

蒸馏废飞机除冰液所得馏分的气相色谱-质谱分析

采用气相色谱-质谱联用技术对蒸馏废飞机除冰液所得馏分进行分析,分离出了3个峰,鉴定出馏分中被蒸出的除冰液有效成分为乙二醇、2-辛酮和2-辛醇,利用峰面积归一化法确定各组分的相对含量为乙二醇占85.78%,2-辛酮占1.54%,2-辛醇占12.68%。     

离子色谱法分析防冻液和切削液中卤族元素

建立了等度离子色谱电导检测器分析防冻液和切削液中卤族元素的方法。采用CarboPacAS19分离柱对分离条件进行了优化,确定柱温为30℃、淋洗液为20mmol·L-1的KOH溶液。在0.10～20.0mg·L-1范围内氟、氯、溴呈良好线性,回收率分别为90.0%~100.4%、80.0%~100.3%、87.2%~97.0%,方法检出限分别为0.005、0.01、0.01mg·kg-1,精密度分别为1.64%~5.46%、0.83%~4.99%、1.07%~5.29%。检测了防冻液和切削液中的卤族元素,效果良好。     

光热超疏水材料的制备与防、除冰性能研究

户外设备表面结冰给人类生活和生产带来了众多不便,研究具有防结冰性能和除冰性能的新一代防、除冰材料对于户外设备的持久稳定运行具有重要意义。本文利用模板法将三氧化二钛（Ti₂O₃）粉末和聚二甲基硅氧烷（PDMS）混合制备具有规则阵列结构的光热超疏水材料,并研究其防结冰性能与光热除冰性能。得益于Ti₂O₃优异的光热性能,制备的材料在100 mW/cm²光照条件下的光热温升可达55℃,冻结在表面的液滴可在200 s内融化,具有优异的光热转换与光热除冰性能。而PDMS材料固化后本征疏水,加规则阵列微结构后赋予材料优异的超疏水性能,其接触角高达153°,滚动角小于5°。无光照时的结冰延迟时间长达1300 s,是无光热材料表面结冰延迟时间的3倍。而在光照时由于其优异的光热性能,液滴在长达6 h的结冰测试中尚未结冰,表明材料具有优异的光热防结冰性能。研究结果论证了利用自然界丰富太阳能进行除冰的可能性,为户外设备表面除冰技术提供新的方式。     

Properties of rigid polyurethane foams prepared from recycled aircraft deicing agent with hexamethylene diisocyanate

Polyurethane (PUR) rigid foams were prepared from recycled aircraft deicing agent (aircraft deicing fluid) with reaction of hexamethylene diisocyanate at temperature of 55°C. The effect of [NCO]/[OH] ratio on properties of microscopic structure, cell size distribution, compressive strength, apparent density, as well as thermal conductivity (k) was studied. Higher [NCO]/[OH] ratio helped achieve better micromorphology, higher apparent density, and compressive strength of the PUR foams. With the [NCO]/[OH] ratio of 0.75 and 0.8, some shrinking happened during foam rising, causing a decrease in total volume of the PUR foam, and leading to higher apparent density as well as sharply increased compressive strength. All PUR foams displayed good thermal insulation properties in this study. With [NCO]/[OH] ratio increased from 0.7 to 0.8, the k value increased significantly from 34.3 to 42.2 mW m^?1 K^?1. The k value here was chiefly governed by the apparent density of the foams, which was in turn a function of the ratio of [NCO]/[OH]. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci., 2013     

The Influence of Pore Solutions Properties on Drying in Cementitious Materials

The drying of cementitious materials can be influenced by the properties of the fluid in the pores. While there are numerous studies on drying, very few explicitly focus on the properties of the pore fluid. This work investigates the influence of deicing salts on the properties of the pore fluid. The change that deicing salts cause in surface tension and viscosity is described in this study as a function of concentration and temperature. As a relatively limited number of measurements have been reported in literature, it can be difficult to describe the properties over a wide range of concentrations or temperatures. To overcome this limitation, this work provides measurements over concentration and temperature ranges. Semiempirical relationships were successfully fitted to the data confirming the possibility to predict viscosity and surface tension changes with temperature and salt concentration. The implications of the fluid properties on the drying behavior are also discussed as they relate to the diffusion coefficient. The models applied effectively predict the initiation of drying. Further improvements are however necessary to describe the diffusion coefficient as function of the degree of saturation in the presence of deicing salts which appear to be needed to account for the chemical interaction between the matrix and the fluid.     

储盐类融雪抑冰材料对沥青混合料性能影响研究进展

为提高冰雪气候条件下沥青路面的运营安全水平,系统介绍了国内外储盐类融雪抑冰材料对沥青混合料性能研究的现状,总结分析了融雪抑冰的主要材料类型、作用机理、评价方法及应用效果等,并探讨了材料对沥青混合料融雪抑冰功能和路用性能的影响。分析表明：储盐类沥青混合料中融雪关键成分氯化物的析出降低了路表水溶液的冰点、路面与冰雪之间的黏附力,显著提高了自身融雪除冰功能;但导致混合料路用性能发生了一定的变化。MFL（Mafilon）材料的掺加,使混合料的各项路用性能均降低,尤其是水稳性能。V-260（Verglimit-260）材料以外掺的方式添加到混合料中,其水稳性能和低温性能均降低。而ICB（icebane）材料的粒径、置换方式、掺量及所用矿料级配等因素均对混合料路用性能有影响。采用高黏改性沥青或掺加添加剂,可有效改善融雪抑冰沥青混合料的路用性能。     

连续式碳纤维电热机场道面融雪化冰数值模拟与验证

为了研究连续式碳纤维发热线的埋深和间距会对机场道面混凝土板表面的温度均匀性产生的影响,以及XPS隔热层的布设对板面融雪化冰效果的优化程度,利用有限元分析软件Ansys建立连续式碳纤维电热机场道面板温升及融雪化冰的瞬态传热模型,主要模拟道面板的温升及化冰过程,结果发现:在连续式碳纤维发热线布置间距≤100 mm、埋深≥50 mm时,板面温度均匀性良好;通过"有效融化时间"和"能源有效利用率"的定量计算,证明XPS隔热层的布设起到了良好的隔热保温的效果,为其在机场道面融雪化冰中的应用提供一定的理论依据.     

Rheological properties of neat epoxy exposed to in‐service aerospace contaminants

We present an experimental study on the rheological properties of a commonly used epoxy resin system (EPIKOTE‐862 resin and EPIKURE‐W curing agent), exposed to a variety of fluids typical of aerospace operations (jet fuel, hydraulic fluids, deicing, detergents, etc.), for a period of up to 6 months, at room temperature for most conditions, and with no concurrent mechanical loading or prior degradation. The specimens were subjected to stress and frequency sweeps with a shear rheometer, while a limited set received also a temperature sweep in a range consistent with aircraft operations. Results indicate that the treated resin samples are linear viscoelastic under these testing conditions. The resin has reasonable chemical resistance to most contaminants of this study, with the exception of two commonly used detergents: an aircraft surface cleaning compound, Penair C5572, and a nonionic detergent, Methyl Ethyl Ketone (MEK). The durability change of the first compound appears triggered by high temperatures only, while the second compound causes a very drastic stiffness loss under several conditions. This drop of performance occurs within a 3‐months period, with no apparent color change or fracture that could prompt visual inspection and repair. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 3961–3971, 2013     

Chemical resistance of carbon fiber-reinforced poly(ether ether ketone) and poly(phenylene sulfide) composites

Studies have been conducted to investigate the aircraft fluid and chemical solvent resistance of the carbon fiber-reinforced poly(phenylene sulfide) (PPS) and poly(ether ether ketone) (PEEK) composites. The solvents and aircraft fluids utilized in this work include hydraulic fluid, paint stripper, JP-4 jet fuel, methyl ethyl ketone, and methylene chloride. The weight gain of the composites as a function of time is measured. Tensile and flexural strength, thermal behavior, and dynamic mechanical properties of the composites are examined. The alteration of crystallinity change of the composites is investigated by X-ray diffraction. It is found that paint stripper degraded the mechanical properties of the composites significantly. Furthermore, crystallization enhancement of the low crystallinity composites in the presence of solvents and aircraft fluids is also observed.     

某型运输机飞行状态下冷凝器风道性能

以某型运输机蒸发循环制冷系统用冷凝器为研究对象,分析了运输机与直升机、小型通航飞机蒸发循环制冷系统工作环境的区别,应用Star CCM+软件进行了仿真建模,通过对冷凝器风道的流体仿真分析,阐述了飞行状态下引起蒸发循环制冷系统压力故障的原因,在此基础上提出了冷凝器风道优化方案,并应用流体仿真分析的方法,验证了优化方案的有效性,最后在该运输机上进行了试飞验证。