西北工业大学学报
西北工業大學學報
서북공업대학학보
JOURNAL OF NORTHWESTERN POLYTECHNICAL UNIVERSITY
2015年
2期
171-177
,共7页
刘南%白俊强%邱亚松%华俊
劉南%白俊彊%邱亞鬆%華俊
류남%백준강%구아송%화준
优化%参数化%效率%升阻比%本征正交分解方法%样本质量
優化%參數化%效率%升阻比%本徵正交分解方法%樣本質量
우화%삼수화%효솔%승조비%본정정교분해방법%양본질량
在飞行器设计过程中为了提高优化设计的寻优精度,设计变量不断增加,从而使整个过程更加复杂且大幅延长设计周期。针对这一问题,基于本征正交分解降阶方法开展气动外形设计空间重构方面的研究。工作针对二维翼型开展,主要目标分为2个方面:①减少优化过程中的气动外形设计参数;②提高设计空间中满足设计约束的样本比例。在Hicks?Henne参数化和POD重构得到设计空间内随机选择20000个样本发现,Hicks?Henne参数化空间中满足设计约束的样本比例不足25%,而重构之后的空间则超过70%。因此,采用P OD方法对设计空间进行重构大大提高了样本质量,同时减少了优化设计参数。以RAE2822进行厚度约束下的单目标升阻比增大优化设计为例分别研究传统的约束处理方法和设计空间重构对优化结果的影响。传统约束处理方法中包括罚函数法和拒绝策略,优化结果表明拒绝策略略优于罚函数法,且无须设置惩罚权重,使用方便。对比重构前后设计空间的优化结果可见,2种传统约束处理方法在32个Hicks?Henne参数化空间中最优设计结果升阻比增加分别为27?61%和28?20%,采用P OD方法重构后的设计空间得到的升阻比提升分别为28?20%和30?63%。因此,设计空间重构前后的优化精度基本类似,而且设计空间重构之后优化设计参数大大减少,设计效率得到明显提升。
在飛行器設計過程中為瞭提高優化設計的尋優精度,設計變量不斷增加,從而使整箇過程更加複雜且大幅延長設計週期。針對這一問題,基于本徵正交分解降階方法開展氣動外形設計空間重構方麵的研究。工作針對二維翼型開展,主要目標分為2箇方麵:①減少優化過程中的氣動外形設計參數;②提高設計空間中滿足設計約束的樣本比例。在Hicks?Henne參數化和POD重構得到設計空間內隨機選擇20000箇樣本髮現,Hicks?Henne參數化空間中滿足設計約束的樣本比例不足25%,而重構之後的空間則超過70%。因此,採用P OD方法對設計空間進行重構大大提高瞭樣本質量,同時減少瞭優化設計參數。以RAE2822進行厚度約束下的單目標升阻比增大優化設計為例分彆研究傳統的約束處理方法和設計空間重構對優化結果的影響。傳統約束處理方法中包括罰函數法和拒絕策略,優化結果錶明拒絕策略略優于罰函數法,且無鬚設置懲罰權重,使用方便。對比重構前後設計空間的優化結果可見,2種傳統約束處理方法在32箇Hicks?Henne參數化空間中最優設計結果升阻比增加分彆為27?61%和28?20%,採用P OD方法重構後的設計空間得到的升阻比提升分彆為28?20%和30?63%。因此,設計空間重構前後的優化精度基本類似,而且設計空間重構之後優化設計參數大大減少,設計效率得到明顯提升。
재비행기설계과정중위료제고우화설계적심우정도,설계변량불단증가,종이사정개과정경가복잡차대폭연장설계주기。침대저일문제,기우본정정교분해강계방법개전기동외형설계공간중구방면적연구。공작침대이유익형개전,주요목표분위2개방면:①감소우화과정중적기동외형설계삼수;②제고설계공간중만족설계약속적양본비례。재Hicks?Henne삼수화화POD중구득도설계공간내수궤선택20000개양본발현,Hicks?Henne삼수화공간중만족설계약속적양본비례불족25%,이중구지후적공간칙초과70%。인차,채용P OD방법대설계공간진행중구대대제고료양본질량,동시감소료우화설계삼수。이RAE2822진행후도약속하적단목표승조비증대우화설계위례분별연구전통적약속처리방법화설계공간중구대우화결과적영향。전통약속처리방법중포괄벌함수법화거절책략,우화결과표명거절책략략우우벌함수법,차무수설치징벌권중,사용방편。대비중구전후설계공간적우화결과가견,2충전통약속처리방법재32개Hicks?Henne삼수화공간중최우설계결과승조비증가분별위27?61%화28?20%,채용P OD방법중구후적설계공간득도적승조비제승분별위28?20%화30?63%。인차,설계공간중구전후적우화정도기본유사,이차설계공간중구지후우화설계삼수대대감소,설계효솔득도명현제승。
In order to increase optimization precision in the design process of aircraft, the design parameters have augmented;this makes the design process more complicated and extends the design cycle. Aiming at this issue, re?construction method of aerodynamic design space using Proper Orthogonal Decomposition is investigated. Main ob?jective is divided into two aspects: one is reduction of the number of aerodynamic design parameters in design process, the other is increase of the ratio of samples which satisfy design constraints. In the Hicks?Henne parame?terization space and reconstructed space by POD, 20000 samples are chosen by LHS method. It is illustrated that the ratio of Hicks?Henne parameterization space satisfying thickness constraints is less than 25%, while the ratio of reconstructed space by POD is about 70%. Therefore, after space reconstruction by POD, sample quality is en?hanced significantly. Moreover, the number of optimization parameters is decreased. The influence of traditional constraint handling methods and reconstructed design space is investigated with the optimization of Cl/Cd of RAE2822 airfoil. Traditional constraint handling methods include penalty function method and death penalty. It is shown that death penalty method is slightly better than penalty function method from optimization results. Addition?ally, there are no penalty factors in death penalty process, which is convenience to use. Comparing the optimization results before and after reconstructed design space, the improvements of Cl/Cd are 27?61% and 28?20% respec?tively for two traditional penalty handing methods in Hicks?Henne parameterization space, while the improvements are 28?51% and 30?63% respectively in reconstructed design space by POD. Therefore, the optimization precision is almost the same before and after space reconstruction, and the number of design parameters is decreased by half;this makes design efficiency improve significantly.