The aim of the current work is to simulate nanonozzle flows using Simplified Bernoulli-Trials collision algorithm in the dsmcfoamstrath solver of OpenFoam. In this test, the inlet Knudsen number, pressure ratio and wall temperature are about 7.781×10-6, 10 and 300 K, respectively. The phenomenon which we observed in nanonozzles is the prevention of formation of supersonic flows in these scales while this behavior does not happen in micronozzles. The reason can be the boundary layer growth due to scale reduction, so that flow is unable to choke. It leads to produce a lower thrust compared to the larger scales. In addition, temperature gradients are smaller than what we observed in micro nozzles.

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