CAJ | 학술논문

在工程实际中，通常采用结构在空气中的自振频率乘以一个经验影响系数得出水中的自振频率，但是通过传统经验影响系数得出的结果与现实相比有很大的误差。本文选用能更加清楚表达水体对叶轮固有频率影响大小的下降系数进行研究。运用基于流固耦合的有限元方法对圆柱模型和两种离心泵叶轮进行模态计算，通过对结果的分析和比较发现：下降系数与结构的固有频率和振型有很大关系，采用分段取值更为合理，模态低阶取小值，高阶取大值，旋转振型取小值。最后对离心泵叶轮模型计算结果进行二次优化，得到更加符合实际的经验下降系数：模态前6阶除第3阶取0.05外，其余取0.15，第7-10阶取0.40。
재공정실제중，통상채용결구재공기중적자진빈솔승이일개경험영향계수득출수중적자진빈솔，단시통과전통경험영향계수득출적결과여현실상비유흔대적오차。본문선용능경가청초표체수체대협륜고유빈솔영향대소적하강계수진행연구。운용기우류고우합적유한원방법대원주모형화량충리심빙협륜진행모태계산，통과대결과적분석화비교발현：하강계수여결구적고유빈솔화진형유흔대관계，채용분단취치경위합리，모태저계취소치，고계취대치，선전진형취소치。최후대리심빙협륜모형계산결과진행이차우화，득도경가부합실제적경험하강계수：모태전6계제제3계취0.05외，기여취0.15，제7-10계취0.40。
Normally,in real project,the natural frequency of a structure in water can be obtained by Nat-ural frequency of the structure in air times an influence coefficient. However, there are big errors between the result obtained by traditional experience influence coefficients and realistic ones. For more clearly ex-pressing the influence on structure by water, depreciation coefficient rather than influence coefficient was chosen to discuss. Finite element method based on the fluid-structure interaction was used in cylinder and impeller model analysis and a new set of experience depreciation coefficient was put forward. The results showed that depreciation coefficient has great relationship with natural frequency and vibration mode. It is reasonable to use segment value suggesting that the small value was applied in the low order level and ro-tation vibration mode, and the high value was applied in the high order. At last, secondary optimization was made in the calculation result of impeller model and the depreciation coefficients which are more con-sistent with realistic ones show that,in 1,2,4,5 and 6 order,the depreciation coefficient is 0.15; in 3 order, the depreciation coefficient is 0.05 and in 7, 8, 9 and 10 order, the depreciation coefficient is 0.40.