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风机矩形蜗壳内部流动特性及其二次流的研究 总被引:1,自引:1,他引:0
—、前言 蜗壳作为离心风机的静止元件,其内部流动状况的好坏对风机性能有着很大的影响。相对运动部件叶轮而言,对蜗壳的研究较少,近年来的一些研究表明,蜗壳内的实际流动非常复杂,用流动解析方法求取蜗壳内的流动损失也并非易事。已有关于蜗壳舌部区域的实验研究大多也是定性的。本文利用单倾斜热线测试系统,在对后向离心风机矩形蜗壳内部流场进行测量的基础上,详细测量了蜗壳内的二次流动及舌部区域的流动状况,旨在为蜗壳的合理设计或数值研究提供基础性资料。 相似文献
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用生石灰和尿素代替沸石加入到乙醇和浓硫酸反应混合物中,并用正交实验方法进行设计和分析,寻找浓硫酸、乙醇、尿素和生石灰的最佳配比。 相似文献
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A new molecular clip based on diethoxycarbonyl glycoluril 5: C42H36N6O6 , has been synthesized and characterized by single-crystal X-ray diffraction. The crystal belongs to orthorhombic, space group Pbca with a=12.7639(5), b=16.9727(7),c=34.2069(14) , V=7410.5(5)3 , Z=8, Dc=1.292 g/cm3 , μ(MoKα)=0.088 mm-1 , F(000)=3024, the final R=0.0655 and wR=0.1566 for 5123 observed reflections with I>2σ(I). The crystal structural analysis shows that intermolecular c-H…O and C-H…N hydrogen bonds stabilized the whole crystal structure. The binding study by fluorescence spectroscope titration showed that the title molecule can selectively recognize Fe3+ with fluorescence quenching. 相似文献
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The title compound 2-(5-(4-chlorophenyl)-1-phenyl-4,5-dihydro-1H-pyrazol-3-yl)- pyridine(C20H16ClN3, Mr = 333.81) has been synthesized and its crystal structure was determined by single-crystal X-ray diffraction. The crystal belongs to monoclinic, space group P21/n with a = 10.9925(12), b = 11.0378(12), c = 14.2751(18) , β = 98.074(11)°, V = 1714.9(3)3, Z = 4, Dc = 1.293 g/cm3, μ(MoKα) = 0.228 mm-1, F(000) = 696, the final R = 0.0521 and wR = 0.1349 for 3495 observed reflections with I 2σ(I). Intermolecular C–H...π interactions and π-π stacking interactions stabilize the crystal structure. The binding study by fluorescence spectroscope titration showed that the title compound can selectively recognize Fe3+ in THF solution with fluorescence quenching. 相似文献
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A new clip molecule 1 based on diethoxycarbonyl glycoluril, C46H34Cl4N4O8, has been synthesized and characterized by single-crystal X-ray diffraction. The crystal belongs to triclinic, space group P1 with a = 11.3674(8), b = 11.3674(8), c = 16.9704(12)A, α = 70.0690(10), β = 72.2310(10), γ = 78.0880(10)°, V = 1993.2(2) A3, Z = 2, Dc = 1.521 g/cm3, μ(MoKα) = 0.361 mm-1, F(000) = 940, the final R = 0.0422 and wR = 0.1144 for 22997 observed reflections with I 2A(I). The crystal structural analysis shows that C–H···O and C–H···Cl hydrogen bonds, C–H···π, C–Cl···π supramolecular interactions, and π-π packing interaction stabilized the whole crystal structure. The binding study by fluorescence spectroscope titration showed that the title molecule can selectively recognize Fe3+ with fluorescence quenching. 相似文献
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