变分量子线性求解算法在高速飞行器定常绕流数值模拟中的应用

Application of Variational Quantum Linear Solver in the Numerical Simulation of Steady Flow Over High-Speed Aircrafts

CFD方法在用于三维大规模复杂流动的空气动力学数值模拟时,面临着计算成本高、模拟时间长等瓶颈问题。近年来,量子计算为航空航天CFD领域带来了新的解决思路,通过利用量子比特的叠加态和纠缠特性,理论上相比于经典计算机能够实现对数级的存储缩减和指数级的效率加速,在处理大规模空气动力学模拟等任务上具有巨大的潜力。聚焦于量子计算技术在航空航天CFD领域的应用探索,针对高速定常流动问题,采用变分量子线性求解器(variational quantum linear solver,VQLS)辅助求解CFD时间离散环节得到的高维线性方程组,进而发展了可以在含噪声中等规模量子(noisy intermediate-scale quantum,NISQ)器件上实现的VQLS-CFD耦合方法。通过三维双椭球模型和探测器火星科学实验室模型的超声速数值模拟测试,验证了VQLS-CFD耦合方法可以实现大规模复杂流动的鲁棒及准确模拟,并产生与试验数据吻合度较高的计算结果,最终获得高可信度的气动预测结果。然而,介绍的量子计算流体力学(quantum computational fluid dynamics,QCFD)方法在计算效率方面尚未达到真正意义上的加速效果,这一现象的突破将依赖量子计算机硬件的持续发展与QCFD算法的不断优化与成熟。

CFD methods encounter bottlenecks such as high computational costs and lengthy simulation time when applied to the numerical simulation of large-scale complex flows.Recently,quantum computing has emerged as a novel solution in the field of aerospace CFD.By harnessing the superposition and entanglement properties of qubits,quantum computing theoretically offers logarithmic storage reduction and exponential efficiency acceleration as compared with classical computers,holding immense potential in tackling tasks of large-scale aerodynamic simulations.This work focused on exploring the application of quantum computing techniques in the field of aerospace CFD.For high-speed steady flows,this work adopted a variational quantum linear solver(VQLS)to assist in solving the high-dimensional linear system produced by the temporal discretization of CFD.Consequently,a VQLS-CFD hybrid method,implementable on noisy intermediate-scale quantum(NISQ)devices,was developed.Through numerical simulations of supersonic flows over the double-ellipsoid and the Mars Science Laboratory(MSL)models,the VQLS-CFD hybrid method was validated to achieve robust and accurate simulations of large-scale complex flows,producing high-quality computational results.However,the quantum computational fluid dynamics(QCFD)method presented in this work has not yet achieved a strict sense of acceleration in terms of computational efficiency.The breakthrough of this phenomenon depends on the continuous development of quantum computer hardware as well as the ongoing optimization and maturity of QCFD algorithms.