The numerical investigation of free radical polymerization (FRP) of methyl methacrylate under mixed feed condition at inlet is made for three microtubular reactor geometries, namely, straight tube, coiled tube, and coil flow inverter reactor. The effect of variation of fluid thermophysical properties (FTPP) (density, viscosity, and thermal conductivity) with reaction along with discrete variation of chemical species diffusion coefficient is studied. Predicted values of monomer conversion, number‐average chain length (DP_n), and polydispersity index (PDI) are found to be systematically lower for variable FTPP case compared to constant FTPP case. But contrary to expectations, results are found to be independent of reactor geometry for either case. Results clearly show the importance of modeling the variation of FTPP especially with respect to conversion. One case of varying diffusion coefficient of each chemical species based on free volume theory with constant FTPP is also simulated. Here again, the results are found to be independent of reactor geometry. Constant thermal conductivity and isothermal reactor condition are found to be good assumptions. This study clearly establishes the need not only for variable FTPP, thus coupling transport processes, but also for incorporating varying diffusion coefficient along with conversion in modeling of FRP in microreactors for better predictions.

中文翻译：

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几何形状的自由基聚合管式微反应器入口完美混合条件的数值研究

对三种微管反应器几何结构，即直管，盘管和盘管流换流器反应器，在混合进料条件下，对甲基丙烯酸甲酯的自由基聚合反应进行了数值研究。研究了流体热物理性质（FTPP）（密度，粘度和导热系数）随反应的变化以及化学物质扩散系数离散变化的影响。单体转化率预测值，数均链长（DP _n），发现与恒定FTPP情况相比，可变FTPP情况的多分散指数（PDI）在系统上较低。但是与预期相反，两种情况的结果均与反应堆的几何形状无关。结果清楚地表明了对FTPP的变化进行建模的重要性，尤其是在转换方面。还模拟了一种基于自由体积理论和恒定FTPP来改变每种化学物质扩散系数的情况。再次发现，结果与反应器的几何形状无关。发现恒定的热导率和等温反应器条件是良好的假设。这项研究清楚地表明，不仅需要可变的FTPP，还需要耦合传输过程，