第一次聲波 的英文怎麼說
中文拼音 [dìyīcìshēngbō]
第一次聲波
英文
first sound-
In this dissertation, the numerical computation for the acoustic radiation problem ( arp ) is studied deeply and systematically in the theory, method and the application technique, based on analyzing the situation of the home and abroad on the numerical computation for the acoustic radiation problem. the calculation formulas of the boundary element method ( bem ) for the exterior acoustic radiation problem in the full - space and half - space are deduced, based on the wave propagation theorem ; the arising of the non - unique solutions, which is associated with the application of the boundary integral equation ( bie ) in acoustic radiation problem, is analyzed and proofed ; the improved combined helmholtz integral equation formulation ( ichief ) is presented to overcome the non - uniqueness problem more effectively and reliably ; the determination of the singular integral coefficients on various occasions is analyzed ; the properties and treatments of the singular integrals with different orders axe studied ; the computation program of the cubic spline ichief is developed and its ability to overcome the non - uniqueness problem and feasibility to discrete the surface coarsely with the sufficient calculation precision are examined through examples
第二章在聲波動理論基礎上，詳細地推導出對應于無限域和半無限域的外部振動聲輻射問題的邊界積分方程計算公式；根據fredholm積分理論，對利用邊界積分方程計算振動聲輻射問題過程中解的非唯一性的產生進行了分析和證明；改進了chief法以提高其克服解的非唯一性的有效性和可靠性；對不同條件下奇性系數的計算、強奇性積分的收斂性及其在變量替換時與普通積分的差異性、不同階奇性積分的計算、數值求積分等進行了研究；開發了三次樣條改進chief法計算軟體，並通過算例考核了該方法在特徵波數處克服解的非唯一性的有效性和在保證計算精度的前提下實現剖分粗化以提高計算效率的可行性。Second, introduce the dyadic wavelet analysis, and use it realized the signal monitor and analysis to the turbine compressor, obtained the detail signal and approach signal at different frequency parts of the compressor s original signal. one type of electromotor that made in china is choose, and it s noise is tested. the noise signal is analyzed by wavelet analysis and spectrum analysis. several high spectral peaks that make people hearing disameniry are found. by contrast with theory calculating results and farther analysis. the cause that producing these spectral peaks is located
其次，介紹了二進小波分析，並應用二進小波分析實現了對透平壓縮機信號的監測分析，得到了壓縮機原始信號在不同頻率段分解的細節信號和逼近信號。用小波分析和譜分析相結合的方法對某國產電機的噪聲進行了分析，找出了人的聽閾不閱的幾個高譜峰位置，進行了空氣動力噪聲計算，通過與理論計算結果進行對比分析，進一步找出了產生該頻閩譜峰的幾個原因，第三，介紹了諧波小波和分形的基本原理。
分享友人