Evaluation of Stall-Level Aerodynamic Modifications for Enhanced Convective Cooling in Dairy Freestalls

Heat stress remains a major constraint in dairy production. Mechanically cross-ventilated barns mitigate thermal load, but conventional in-line freestall layouts create wake interference that reduces airflow to downstream cows. This study used computational fluid dynamics (CFD), with numerical verification and benchmarking against empirical bluff-body correlations, to evaluate stall-level strategies for improving cow body sensible convective heat transfer. Simulations represented a head-to-head freestall section with anatomically realistic Holstein cows at inlet velocities of 0.5–3.0 m s−1. Five configurations were examined: baseline in-line, staggered, staggered with an overhead baffle, single 45° vertical deflector, and double vertical deflectors. The staggered configuration increased the mean second-row cow body sensible convective heat-transfer rate by approximately 15–20% relative to the baseline, while the single deflector increased it by up to 29%. At 3.0 m s−1, the double-deflector configuration produced an approximate 34% increase. A representative AOZ analysis at 1.0 m s−1 showed that greater heat-transfer performance did not necessarily correspond to lower plane-wide velocity variation. These findings demonstrate that stall-level aerodynamic modifications can enhance cow body sensible convective heat transfer under controlled modeling assumptions.