author = "Sebasti{\~a}o, Israel Borges and Santos, Wilson Fernando Nogueira 
          affiliation = "{Instituto Nacional de Pesquisas Espaciais (INPE)} and {Instituto 
                         Nacional de Pesquisas Espaciais (INPE)}",
                title = "Impact of surface discontinuities on flowfield structure of a 
                         micronozzle array",
              journal = "Nanoscale And Microscale Thermophysical Engineering",
                 year = "2014",
               volume = "18",
               number = "1",
                pages = "54--79",
                month = "Jan.",
             keywords = "DSMC, rarefied flow, MEMS, micronozzle, supersonic flow.",
             abstract = "This work carries out two-dimensional numerical simulations of 
                         rarefied gas flow in convergent-divergent micronozzles. Such a 
                         device is considered part of a micronozzle array. Although 
                         previous studies have investigated micronozzles with continuous 
                         divergent surfaces, the present work evaluates the impact of the 
                         surface smoothness on the flowfield structure by including 
                         discontinuities on the divergent contour. Such a scenario was not 
                         previously investigated. As a secondary goal, detailed physical 
                         explanations are given for those flow features reported but not 
                         extensively discussed in previous micronozzle studies. A direct 
                         simulation Monte Carlo method is employed to describe these flows 
                         due to the moderate rarefaction degree typically observed in 
                         microdevices. The results pointed out the sensitivity of the 
                         macroscopic propertiesvelocity, pressure, and temperaturedue to 
                         the geometric variations on the divergent surface. In addition, 
                         Knudsen number distributions are computed to map nonequilibrium 
                         flow regions. The results indicated that the proposed surface 
                         discontinuities do not play the main role in the investigated 
                         micronozzle flows. This finding was not previously reported for 
                         micronozzle flows and contradicts the expected behavior in 
                         macroflows, where shock waves and/or expansion waves arise in 
                         supersonic flows experiencing abrupt changes in the flow 
                  doi = "10.1080/15567265.2013.840344",
                  url = "http://dx.doi.org/10.1080/15567265.2013.840344",
                 issn = "1556-7265 and 1556-7273",
                label = "isi 2014-05 SebastiaoSant:2014:IMSUDI",
             language = "en",
        urlaccessdate = "26 nov. 2020"