Table 2.

Boundary condition setups in CFD simulation.

Boundary name	Boundary condition
Skylight inlet	Velocity inlet, velocity is different with various running conditions (idling: 0.57 m/s, low bus speed: 2.09 m/s, high bus speed: 5.37 m/s), temperature is 11 °C, turbulent intensity is 5%.
Skylight outlet	Outflow, velocity is same as skylight inlet, temperature is different with various running conditions (idling: 24 °C, low bus speed: 23 °C, high bus speed: 21 °C), turbulent intensity is 5%.
Glass at wall surface	No slip wall, heat flux is determined by energy balance estimates (idling: 92.89 W/m2, low bus speed: 79.00 W/m2, high bus speed: 56.63 W/m2).
Index-patient side radiator	Standard wall function, no slip wall, heat flux is 100 W/m2, surface area is 3.38 m2.
Opposite side radiator (closed)	Standard wall function, no slip wall, heat flux is 0 W/m2, surface area is 3.38 m2.
Wall of bus, luggage rack, seat	Standard wall function, no slip wall, heat flux is 0 W/m2.
Nose (except index patient)	Mass-flow-outlet, mass flow rate is 9.23 × 10−5 kg/s, Nostril area is 2.87 × 10−4 m2.
Mouth of index patient	Velocity inlet, exhaled airflow velocity is 1.5 m/s (in a direction paralleling to Y-axis), temperature is 32 °C.
Other body surface	Standard wall function, no slip wall, convective heat is 50 W for each person.