A representative subarray method for radiation hydrodynamic modelling of large floating arrays with modularized configuration

Radiation hydrodynamic modelling of large floating arrays requires constructing immense influence coefficient matrices, with computational costs increasing rapidly with array size. Because these arrays typically feature modularized configurations, the surrounding-module arrangements of different modules exhibit repeated spatial patterns. To reduce computational cost, a representative subarray method is proposed based on arrangement repetition and the distance-dependent decay of radiation interactions. In this approach, a representative subarray is selected to encompass all required surrounding-module arrangements within an effective radiation range, and radiation hydrodynamic modelling is performed once for this subarray at each evaluated frequency. Full-array global coefficient matrices are subsequently constructed by identifying and matching the required submatrices based on relative module positions, while out-of-range coupling terms are set to zero. Taking square arrays as case studies, the present method is validated against direct full-array modelling through comparisons of radiation hydrodynamic coefficients and system modal frequencies. Results demonstrate excellent agreement, with greater computational savings for larger arrays. Significantly, for a 10 × 10 array, computational time is reduced to 2.07% of that required by direct full-array modelling. Furthermore, the proposed method successfully captures position-dependent radiation effects and lower-order collective motions that uncoupled single-module approximations cannot resolve. Overall, this method provides an accurate and computationally efficient approach to radiation hydrodynamic modelling of large modularized floating arrays.