Preventing Airborne Disease Transmission: Review of Methods for Ventilation Design in Health Care Facilities

Table 2

Summary of turbulence modeling approaches (with representative number of required computational cells and computational time to simulate one hour of ventilation flow in a hospital inpatient room).

Turbulence model	Advantages	Disadvantages	Cells	Time
DNS^1	Resolves eddies of all lengths	Computationally very expensive	10^10	Years
LES^2	Resolves large eddies	Computationally expensive	10^8	Months
DES^3	Computationally economic	Difficult to implement	10^7	Weeks
RANS^4	Computationally economic	Less accurate, difficult to converge	10^6	Days

¹DNS: direct numerical simulation, ²LES: large eddy simulation, ³DES: detached eddy simulation, ⁴RANS: Reynolds averaged Navier-Stokes.