1. A data center comprising: an air-conditioning unit, and one or more electronics racks; and a computer system comprising: a memory; and a processor in communications with the memory, wherein the computer system performs a method, the method comprising: providing a data center layout optimized for data center energy efficiency, the data center being a bounded domain and the providing comprising: performing computational fluid dynamics modeling of the bounded domain, the performing comprising: processing the bounded domain to automatically locate within the bounded domain at least one viscous region of the bounded domain, the processing comprising: dividing the bounded domain into a plurality of cells, and determining a flow characteristic value for cells of the plurality of cells of the bounded domain; defining turbulence characteristic cutoff values using, at least in part, multiple cutoff percentiles of cells and the determined flow characteristic values, and defining ranges between the defined characteristic cutoff values with respective χ values, one respective χ value being a highest χ value ‘R’, where ‘R’ is a selected viscous region cell radius; assigning, using the respective χ values of the ranges, χ values to cells of the plurality of cells based on the cells determined flow characteristic values in comparison to the characteristic cutoff values; selectively increasing the assigned χ value of at least one cell of the plurality of cells, the selectively increasing comprising increasing the assigned χ value of the at least one cell where the at least one cell shares a border with at least one seed cell of the plurality of cells, the at least one seed cell having the highest χ value ‘R’; and identifying a viscous region of the at least one viscous region where multiple contiguous cells of the plurality of cells have χ values equal to or greater than a set χ value threshold; evaluating the at least one viscous region by performing viscous domain solve for the at least one viscous region within the bounded domain; providing a model of the bounded domain using, at least in part, results of the viscous domain solve; and using the model in providing the data center layout optimized for energy efficiency of the data center, wherein the data center is configured based on the model.