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为了研究不同的冷却流道布局对大面积比铣槽喷管三维再生冷却槽道在循环工作条件下的热结构响应和低周疲劳寿命的影响,采用有限体积流—热耦合计算方法、非线性有限元热—结构耦合分析方法和局部应变法对比分析了冷却剂单向逆流、单向顺流和先顺向流动再逆向流动的来回流三种流道布局方案。计算结果表明,铣槽喷管内衬最严重的节点应变主要发生在喷管前部内衬燃气侧壁面与肋条对称面及槽道对称面相交的危险区域,这也是节点低周疲劳寿命最小的位置;铣槽内衬节点的应变时间历程主要由塑性应变决定,肋条与槽道对称面上内衬节点的热结构响应存在较大差异;采用冷却剂单向逆流布局的铣槽喷管内衬节点应变幅和残余应变最大,导致喷管疲劳使用寿命最短;采用冷却剂单向顺流布局的铣槽喷管内衬节点应变幅和残余应变最小,导致喷管低周疲劳寿命最长;采用冷却剂来回流布局的再生冷却喷管铣槽内衬的热结构响应和疲劳使用寿命均处于上述两者之间,但取消了喷管尾部集合器和外置冷却剂供给管路等易失效的部件。
In order to study the effect of layout of different cooling channels on the thermal structure response and the low-cycle fatigue life of large-area three-dimensional regenerative cooling channels of slotted nozzle nozzles under cyclic working conditions, the finite volume flow-thermal coupling method was used to calculate the nonlinearity The finite element thermal-structural coupling analysis method and the local strain method are compared to analyze the three kinds of flow channel layout schemes of unidirectional countercurrent, unidirectional co-current and forward-reverse flow. The calculation results show that the most serious node strain of slotted nozzle lamination mainly occurs in the dangerous area where the gas side wall lining the front of the nozzle intersects the rib symmetry plane and the channel symmetry plane, which is also the node with the lowest low-cycle fatigue life Position of the milling groove lining joints is mainly determined by the plastic strain and the thermal structure response of the lining joints on the symmetry plane of the grooves is quite different. The maximum strain rate and residual strain of the joints can lead to the shortest service life of the nozzle. The strain amplitude and the residual strain of the nozzle joints of the slotted nozzle with coolant unidirectional downstream flow are the smallest, resulting in the longest low-cycle fatigue life of the nozzle. Regenerative cooling nozzles with coolant back and forth layout The thermal structural response and fatigue life of the milling slot liner are in between, but the nozzle end collectors and external coolant supply lines are eliminated part.