CAJ | 학술논문

采用三维Taylor?Green涡作为研究对象，利用工程中常用的低阶数值格式，研究格式本身的数值误差对大涡模拟计算的影响。结果表明：三种数值格式的数值耗散行为都与亚格子模型行为类似，即在小雷诺数下，流场比较光滑时，耗散很小，当雷诺数增加，流动转捩为湍流，流场梯度增大，耗散显著增大。对于MUSCL格式和二阶有界中心格式，在高雷诺数下，亚格子尺度模型没有明显改善计算结果，但也没有使计算结果恶化。中心格式相比其它两种格式，数值耗散最小，但是在高雷诺数湍流情况下，中心格式的数值耗散仍然主导了能量的耗散，再添加亚格子模型，计算结果反而变得稍差。对于工程中的低阶格式而言，采用中心格式计算大涡模拟是比较好的选择，而且在计算不存在稳定性问题时，采用不添加亚格子模型的隐式大涡模拟效果更好。
채용삼유Taylor?Green와작위연구대상，이용공정중상용적저계수치격식，연구격식본신적수치오차대대와모의계산적영향。결과표명：삼충수치격식적수치모산행위도여아격자모형행위유사，즉재소뢰낙수하，류장비교광활시，모산흔소，당뢰낙수증가，류동전렬위단류，류장제도증대，모산현저증대。대우MUSCL격식화이계유계중심격식，재고뢰낙수하，아격자척도모형몰유명현개선계산결과，단야몰유사계산결과악화。중심격식상비기타량충격식，수치모산최소，단시재고뢰낙수단류정황하，중심격식적수치모산잉연주도료능량적모산，재첨가아격자모형，계산결과반이변득초차。대우공정중적저계격식이언，채용중심격식계산대와모의시비교호적선택，이차재계산불존재은정성문제시，채용불첨가아격자모형적은식대와모의효과경호。
Several low?order numerical schemes were evaluated for their suitability in large?eddy simulations based on 3D Taylor?Green vortex, with and without a subgrid?scale model. It shows that dissipation characteristics of three numerical schemes used are similar to a subgrid?scale model. At lower Reynolds numbers, flow fields are relatively smooth, numerical dissipation is lower; As Reynolds number increasing, transition to turbulence occurs and numerical dissipation grows greatly. For MUSCL and bounded centered schemes, subgrid?scale model has a little influence on results at high Reynolds numbers. The second?order central scheme exhibits lower dissipation, but at higher Reynolds numbers numerical dissipation still dominates total energy dissipation of flow. With an explicit subgrid?scale model the results even become worse. Therefore, for large eddy simulations in engineering, the second order central scheme is suitable, particularly without an explicit subgrid?scale model.