Mixing characteristics in two innovative variants of coiled flow inverter, namely, symmetrical compact coiled flow inverter (SCCFI) and asymmetrical compact coiled flow inverter (ACCFI) are assessed against that of standard coiled flow inverter (CFI), through experimental and numerical analysis conducted under diffusion-free laminar flow condition $(2.35\le N_{De}\le 11.5;7.55\le N_{\mathrm{Re}}\le 36.96)$. The experimental study involves the comparison of step input residence time distribution (RTD) curves to examine (i) the narrowing effects with the increase in Dean number until a unique RTD is achieved, and (ii) the effect of bends on narrowing of RTD. Results show that maximum narrowing of RTD is achieved in SCCFI, followed by ACCFI and standard CFI, and the unique RTDs obtained comply with the narrowing trends: SCCFI at N_De = 5.3, ACCFI at N_De = 3.5 and standard CFI at N_De = 3. The experimental trends are interpreted through an elaborate CFD analysis that predicts the secondary flow features as well as RTD curves. The CFD results show Dean vortices and flow inversion intensifying with Dean number that explains the narrowing effect with the increase in Dean number. RTDs obtained at intermediate bends in all the geometries, show the sequential narrowing with increasing number of bends, thus establishing the beneficial role of complete flow inversion on radial mixing.

在盘绕流逆变器，两个创新变体混合特性即，对称的紧凑盘绕流逆变器（SCCFI）和非对称紧凑盘绕流逆变器（ACCFI）时，判定针对该标准螺旋流动反转件（CFI），通过实验和下进行数值分析的无扩散层流条件$（2.35\le {ñ}_{dË}\le 11.5;7.55\le {ñ}_{\mathrm{回覆}}\le 36.96）$。实验研究包括比较阶跃输入停留时间分布（RTD）曲线，以检查（i）随着Dean数的增加而变窄的效果，直到获得唯一的RTD，以及（ii）弯曲对RTD变窄的影响。结果表明RTD的该最大变窄在SCCFI实现，随后ACCFI和标准CFI，以及独特的RTD获得符合变窄的趋势：在SCCFI Ñ_德 = 5.3，在ACCFI Ñ_德 = 3.5和标准CFI在Ñ_德 =3。通过精心设计的CFD分析来解释实验趋势，该CFD分析可预测次要流动特征以及RTD曲线。CFD结果显示，随着Dean数的增加，Dean涡旋和流动反演加剧，这说明了随着Dean数的增加而产生的缩小效应。在所有几何形状的中间折弯处获得的RTD随折弯数量的增加而显示出依次变窄的趋势，从而确立了完全流动反演对径向混合的有益作用。