char: HE INTRODUCED THE CONCEPT OF BOUNDARY LAYER AND FOUNDED MATHEMATICAL AERODYNAMICS BY CALCULATING AIR FLOW IN THE DOWN WIND DIRECTION
phn: HH IY IH N T R AH D UW S T DH AH K AA N S EH P T AH V B AW N D ER IY L EY ER AH N D F AW N D IH D M AE TH AH M AE T IH K AH L EH R OW D AY N AE M IH K S B AY K AE L K Y AH L EY T IH NG EH R F L OW IH N DH AH D AW N W IH N D D ER EH K SH AH N