英语翻译

题目

英语翻译
As mentioned above,when the velocity on the duct induced by propeller is computed,two different treatments are applied.Fig.4 gives the comparison of results obtained by two treatments,in which“CAV”and“NAV”denote circumferentially averaged and not averaged treatments respectively.It is seen from Fig.4 that the thrust of duct at lowadvance coefficient can be improved when the induced velocity of propeller to duct is not circumferentially averaged,namely the wake behind the duct exists.This conclusion is coincident with that from Ref.[7].
In Figs.5 and 6,parameter BTKI is a coefficient determining the hydrodynamic pitch angle in the transition region of the wake of propeller.Usually BTKI=0.5 is adopted by panel method for the single propeller.It can be seen from Figs.5 and 6 that BTKI=0.43 gives better results for the case of JD7704 duct+KA propeller series and BTKI=0.48 for the case of JD7704 duct + JDC propeller series.
In the numerical calculations of panel method,the

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