Air flow direction in a temperature controlled railroad freight car

A car body for a temperature-controlled railroad freight car, comprising:

• (a) a pair of opposite side walls;
• (b) a pair of opposite end walls defining a length of said car body;
• (c) a roof interconnected with said side walls and end walls;
• (d) a horizontal ceiling adjacent said roof and extending generally horizontally over said length of said car body;
• (e) a plenum bottom panel located a predetermined distance beneath said ceiling;
• (f) a pair of plenum side members extending downward from said ceiling to said plenum bottom panel, said ceiling, plenum bottom panel, and plenum side members defining a plenum having an inflow end located a short distance from one of said end walls and extending longitudinally along said car body from said inflow end;
• (g) an inlet opening defined in one of said end walls of said car body adjacent said inflow end of said plenum and extending lower than said plenum bottom panel at said inflow end;
• and
• (h) a diverter extending transversely within said car body adjacent said inflow end of said plenum and having a front face extending at an upward slope from said inlet opening to said plenum, said diverter having a lower margin located at a lower height than said plenum bottom panel and having a transition portion located adjacent said inflow end of said plenum, and said transition portion of said diverter including a shoulder and an inner margin portion extending from said shoulder into said plenum and sloping gently downwardly away from said shoulder so as to direct a flow of air from said inlet opening in said end wall to enter said inflow end of said plenum smoothly and to flow smoothly along said plenum.