Algebraic model of turbulent flow in ducts of rectangular cross-section with rounded corners

Of increasing importance are nowadays ducts of rectangular cross-section with large-radius rounded corners. They are used for large air flow rates at low pressure levels — typically for air flow distribution in buildings ventilation and heating systems. Paper develops an analytic model of turbulent flows in these ducts. It makes possible in particular evaluation of velocity profiles – and volume flow rates as a function of duct cross-section shapes. The model was validated by comparing the solutions with full-scale duct laboratory measurements.