Experimental Study of Jet Flow Noise Characteristics of an Axial Symmetric Straight Nozzle
轴对称直喷管的射流噪声特性实验研究

Type 3560C multi-analysis system manufactured by B.K. Company in Denmark was employed to explore jet flow noise characteristics. The subsonic and transonic jet flow noise generated by an axial symmetric straight nozzle under different pressure ratios was measured. Outside flow field characteristics along axial and slice direction were measured and analyzed respectively to determine the detector position, and the noises come from different positions to model section were compared. The noise variation trend was obtained when the frequency is less than 5000Hz. Results indicate that jet flow noise shoots up along with pressure ratio increasing at lower frequencies. Jet flow noise arrives at the highest point and fluctuates when the pressure ratio approaching the given value. After that, jet flow noise changes gradually and presents a downward trend.