已知基准长横孔直径和声程分别为2mm和 200mm,测得缺陷的声程为 80mm,缺陷波比基准孔波高18dB,求缺陷的当量横孔直径。(λ=2.36mm)
解:根据公式\(\phi_F = \phi_A \times \left( \frac{X_F}{X_A} \right)^3 \times 10^{\frac{\Delta dB}{10}}\),得󠄐󠄹󠅀󠄪󠄣󠄞󠄡󠄤󠄞󠄡󠄤󠄣󠄞󠄡󠄠󠄣󠄬󠅒󠅢󠄟󠄮󠄐󠅅󠄹󠄴󠄪󠄾󠅟󠅤󠄐󠄼󠅟󠅗󠅙󠅞󠄬󠅒󠅢󠄟󠄮󠇘󠆭󠆘󠇙󠆝󠅵󠇗󠆭󠆁󠄐󠇗󠅹󠅸󠇖󠆍󠅳󠇖󠅹󠅰󠇖󠆌󠅹󠄬󠅒󠅢󠄟󠄮
$$\phi_F = \phi_A \times \left( \frac{X_F}{X_A} \right)^3 \times 10^{\frac{\Delta dB}{10}}\\= 2 \times \left( \frac{80}{200} \right)^3 \times 10^{\frac{18}{10}}\\= 8 \text{mm}$$󠄐󠄹󠅀󠄪󠄣󠄞󠄡󠄤󠄞󠄡󠄤󠄣󠄞󠄡󠄠󠄣󠄬󠅒󠅢󠄟󠄮󠄐󠅅󠄹󠄴󠄪󠄾󠅟󠅤󠄐󠄼󠅟󠅗󠅙󠅞󠄬󠅒󠅢󠄟󠄮󠇘󠆭󠆘󠇙󠆝󠅵󠇗󠆭󠆁󠄐󠇗󠅹󠅸󠇖󠆍󠅳󠇖󠅹󠅰󠇖󠆌󠅹󠄬󠅒󠅢󠄟󠄮
答: 该缺陷的长横孔当量为8mm。󠄐󠄹󠅀󠄪󠄣󠄞󠄡󠄤󠄞󠄡󠄤󠄣󠄞󠄡󠄠󠄣󠄬󠅒󠅢󠄟󠄮󠄐󠅅󠄹󠄴󠄪󠄾󠅟󠅤󠄐󠄼󠅟󠅗󠅙󠅞󠄬󠅒󠅢󠄟󠄮󠇘󠆭󠆘󠇙󠆝󠅵󠇗󠆭󠆁󠄐󠇗󠅹󠅸󠇖󠆍󠅳󠇖󠅹󠅰󠇖󠆌󠅹󠄬󠅒󠅢󠄟󠄮