气－固流动系统无干扰测量设备的新进展

为了在气－固流动系统过程中确定运输特性，证实理论预报和仪设计程序公式化，必须对气－固两相流的各相质量流量、密度和局部地区的流速进行测量，对于某种相（诸如一群固体颗粒）的密度进行直接测量时需要有一种基本测量标准，激光多普勤相测定仪在一定条件下可以测定局部地区的瞬时密度，因而可用作基本测量标准，其它光学方法及中子束方法由于需要用质量流量进行标定，因而只能用作间接的测量标准，本文对无干扰测试设备的新进展进行了综述，对激光多普勒测速仪（ＬＤＶ）、相多普勤颗粒分析仪（ＰＤＰＡ）直至核磁共振测速仪的性能、限制因素及应用前景作了概述和讨论。

RECENT ADVANCES iN NON-INTRUSIVE INSTRUMEN-TATION FOR GAS-SOLID FLOW SYSTEMS

Measurements of local velocity,density'and mass flow of phases of a gas-solid suspen-sion are needed in determining transport properties ,validating theoretical predictions'andformulating design procedures of processing systems.A primary standard for direct measure-ment of density of a phase such as a cloud of solid particles is needed.A laser phase Dopplerdevice,within certain restrictions, may give local instantaneous density,while other opticalmethods and neutron beam remain secondary standards based on mass flow calibrations.Anoverall review including recent results is presented on non-intrusive instruments i the capabil-ities,limitations,and future possibilities of devices ranging from laser Doppler velocimetry(LDV) and phase Doppler particle analyzer(PDPA3 to nuclear magnetic resonance imaging(NMRI)are outlined and discussed.