Flight Suvarnabhumi Airport departs from Bangkok Suvarnabhumi Airport at 18:35 and arrives at Wuhan Wuhan Tianhe International Airport at 23:15.
The flighttime is about 3h 40m. The distance travelled ("as the bird flies"): 1586 Km. So the average speed is roughly 433 Km.
There is an 1 hour time difference between Bangkok and Wuhan