钝化外形对旋成体气动性能的影响

计算机辅助工程 / 2018年01月19日 10:51

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摘要: 为考察钝化外形对高超声速飞行器气动性能的影响,基于CFD分析,针对典型旋成体比较2种不同钝化外形(钝化半径均匀/非均匀)的气动性能.结果表明:在较小的钝化半径/高度下,由于前缘流向投影面积占整个旋成体流向投影面积比例较小,前缘气动性能对整个旋成体气动性能影响不大;但是,随着钝化半径/高度的增加,前缘气动性能对整个旋成体气动性能影响会逐渐增大.

关键词: 旋成体; 高超声速; 飞行器; 前缘; 气动力; CFD

中图分类号: V423.8;TB115.1文献标志码: B

Abstract: To study the effect of blunt shapes on the aerodynamic performance of hypersonic aircraft, based on CFD analysis, the aerodynamic performance of two different blunt shapes(the blunt radius are uniform or nonuniform) are compared for typical bodies of revolution. The results show that, under the smaller blunt radius/height, because the projection area in flow direction of leadingedge accounts for a small proportion of the projection area in flow direction of whole bodies of revolution, the leadingedge aerodynamic performance has a little effect on the aerodynamic performance of the whole bodies of revolution; however, with the increase of blunt radius/height, the effect of leadingedge aerodynamic performance on the aerodynamic performance of whole bodies of revolution increases gradually.

Key words: body of revolution; hypersonic speed; aircraft; leadingedge; aerodynamic force; CFD

引言

飞行器在高超声速飞行时,来流会对前缘产生较严重的气动热,而前缘驻点热流更严重.为改善这一情况,科学家针对驻点热流进行很多研究[19],结果均表明驻点热流与其驻点曲率半径的平方根成反比.采用较大的钝化半径可有效减小热流,但也会增强头部弓形激波,导致激波阻力急剧增加.文献[10]提出一种钝化半径非均匀的外形,基于数值模拟方法求解高超声速冻结流流场获得前缘热流分布,并应用遗传算法求解获得一个新外形(优化外形).结果表明,在相同的钝化半径/高度下,优化外形最大热流峰值比相应的圆弧钝化热流密度峰值减小大约20%.采用2种钝化外形时热流Q和压力P分布比较见图1和2,可以看出,优化前缘驻点附近热流较圆弧前缘有较明显下降,但同时压力分布也有较大差别,优化外形在驻点附近的压力明显高于圆弧钝化.优化外形较圆弧在防热方面有较大的优势,同时又会对气动力产生较大影响.为考察2种不同钝化外形对飞行器气动力性能的影响,针对高超声速旋成体,基于CFD数值模拟分析,开展2种不同钝化外形气动力性能的比较,分析不同钝化半径/高度在一定攻角变化范围内变化时对旋成体气动力性能的影响.

由图9可知:攻角在小范围内变化时,在相同的钝化外形下,升阻比随攻角的增大逐渐增大;在较小的钝化半径/高度下,优化外形的升阻比在相同的攻角下比圆弧外形的升阻比略低,但两者升阻比相差较小;随着钝化半径/高度的增加,由于阻力增加明显高于升力增加,两者升阻比差随攻角增大逐渐增大.

4结束语

通过对模型流场进行数值计算,得到优化外形钝化和圆弧钝化的流场,通过对2种不同钝化外形在不同钝化半径/高度下气动性能的分析,发现在较小的钝化半径/高度下,2种不同钝化外形对气动力性能影响不大,并且在小攻角范围内2种不同钝化外形对气动力性能影响也不大.随着钝化半径/高度的增大,2种不同钝化外形对气动力性能差别逐渐增大.

参考文献:

[1]REGINALD von DRIEST E. The problem of aerodynamic heating[J]. Aeronautical Eng Review, 1956, 15(10): 2641.

[2]LEES L. Laminar heat transfer over bluntnosed bodies at hypersonic flight speeds[J]. J Jet Propulsion, 1956, 26(4): 259269.

[3]FAY J A, RIDDELL F R. Theory of stagnation point heat transfer in dissociated air[J]. J Aeronautical Sci, 25, 1958, 25(1): 7385.

[4]KEMP N H, ROSE P H, DETRA R W. Laminar heat transfer around blunt bodies in dissociated air[J]. J Aeronautical Sci, 1959, 26(7): 421430.

[5]ROSE P H, STARK W. Stagnation point heat transfer measurements in dissociated air[J]. J Aeronautical Sci, 1958, 25(2): 8697.

[6]ROSE P H, STANKEVICS J O. Stagnation point heat transfer measurements in partially ionized air[J]. AIAA J, 1963, 1(12): 27522763.

[7]MARVIN J G, DEIWERT G S. Convective heat transfer in planetary gases[R]. Washington D C: NASA, 1965.

[8]SUTTON K, GRAVES R A. A general stagnationpoint convectiveheating equation for arbitrary gas mixtures[R]. Washington D C: NASA, 1971.

[9]ANDERSON J D. Hypersonic and high temperature gas dynamics[M]. Reston: AIAA, 2006.

[10]CUI K, HU S C. Shape design to minimize the peak heatflux of blunt leadingedge[C]//Proc 51st AIAA Aerospace Sci Meeting AIAA 20130233. Texas, 2013: 233259.(编辑武晓英)

摘要: 为考察钝化外形对高超声速飞行器气动性能的影响,基于CFD分析,针对典型旋成体比较2种不同钝化外形(钝化半径均匀/非均匀)的气动性能.结果表明:在较小的钝化半径/高度下,由于前缘流向投影面积占整个旋成体流向投影面积比例较小,前缘气动性能对整个旋成体气动性能影响不大;但是,随着钝化半径/高度的增加,前缘气动性能对整个旋成体气动性能影响会逐渐增大.

关键词: 旋成体; 高超声速; 飞行器; 前缘; 气动力; CFD

中图分类号: V423.8;TB115.1文献标志码: B

Abstract: To study the effect of blunt shapes on the aerodynamic performance of hypersonic aircraft, based on CFD analysis, the aerodynamic performance of two different blunt shapes(the blunt radius are uniform or nonuniform) are compared for typical bodies of revolution. The results show that, under the smaller blunt radius/height, because the projection area in flow direction of leadingedge accounts for a small proportion of the projection area in flow direction of whole bodies of revolution, the leadingedge aerodynamic performance has a little effect on the aerodynamic performance of the whole bodies of revolution; however, with the increase of blunt radius/height, the effect of leadingedge aerodynamic performance on the aerodynamic performance of whole bodies of revolution increases gradually.

Key words: body of revolution; hypersonic speed; aircraft; leadingedge; aerodynamic force; CFD

引言

飞行器在高超声速飞行时,来流会对前缘产生较严重的气动热,而前缘驻点热流更严重.为改善这一情况,科学家针对驻点热流进行很多研究[19],结果均表明驻点热流与其驻点曲率半径的平方根成反比.采用较大的钝化半径可有效减小热流,但也会增强头部弓形激波,导致激波阻力急剧增加.文献[10]提出一种钝化半径非均匀的外形,基于数值模拟方法求解高超声速冻结流流场获得前缘热流分布,并应用遗传算法求解获得一个新外形(优化外形).结果表明,在相同的钝化半径/高度下,优化外形最大热流峰值比相应的圆弧钝化热流密度峰值减小大约20%.采用2种钝化外形时热流Q和压力P分布比较见图1和2,可以看出,优化前缘驻点附近热流较圆弧前缘有较明显下降,但同时压力分布也有较大差别,优化外形在驻点附近的压力明显高于圆弧钝化.优化外形较圆弧在防热方面有较大的优势,同时又会对气动力产生较大影响.为考察2种不同钝化外形对飞行器气动力性能的影响,针对高超声速旋成体,基于CFD数值模拟分析,开展2种不同钝化外形气动力性能的比较,分析不同钝化半径/高度在一定攻角变化范围内变化时对旋成体气动力性能的影响.

由图9可知:攻角在小范围内变化时,在相同的钝化外形下,升阻比随攻角的增大逐渐增大;在较小的钝化半径/高度下,优化外形的升阻比在相同的攻角下比圆弧外形的升阻比略低,但两者升阻比相差较小;随着钝化半径/高度的增加,由于阻力增加明显高于升力增加,两者升阻比差随攻角增大逐渐增大.

4结束语

通过对模型流场进行数值计算,得到优化外形钝化和圆弧钝化的流场,通过对2种不同钝化外形在不同钝化半径/高度下气动性能的分析,发现在较小的钝化半径/高度下,2种不同钝化外形对气动力性能影响不大,并且在小攻角范围内2种不同钝化外形对气动力性能影响也不大.随着钝化半径/高度的增大,2种不同钝化外形对气动力性能差别逐渐增大.

参考文献:

[1]REGINALD von DRIEST E. The problem of aerodynamic heating[J]. Aeronautical Eng Review, 1956, 15(10): 2641.

[2]LEES L. Laminar heat transfer over bluntnosed bodies at hypersonic flight speeds[J]. J Jet Propulsion, 1956, 26(4): 259269.

[3]FAY J A, RIDDELL F R. Theory of stagnation point heat transfer in dissociated air[J]. J Aeronautical Sci, 25, 1958, 25(1): 7385.

[4]KEMP N H, ROSE P H, DETRA R W. Laminar heat transfer around blunt bodies in dissociated air[J]. J Aeronautical Sci, 1959, 26(7): 421430.

[5]ROSE P H, STARK W. Stagnation point heat transfer measurements in dissociated air[J]. J Aeronautical Sci, 1958, 25(2): 8697.

[6]ROSE P H, STANKEVICS J O. Stagnation point heat transfer measurements in partially ionized air[J]. AIAA J, 1963, 1(12): 27522763.

[7]MARVIN J G, DEIWERT G S. Convective heat transfer in planetary gases[R]. Washington D C: NASA, 1965.

[8]SUTTON K, GRAVES R A. A general stagnationpoint convectiveheating equation for arbitrary gas mixtures[R]. Washington D C: NASA, 1971.

[9]ANDERSON J D. Hypersonic and high temperature gas dynamics[M]. Reston: AIAA, 2006.

[10]CUI K, HU S C. Shape design to minimize the peak heatflux of blunt leadingedge[C]//Proc 51st AIAA Aerospace Sci Meeting AIAA 20130233. Texas, 2013: 233259.(编辑武晓英)

摘要: 为考察钝化外形对高超声速飞行器气动性能的影响,基于CFD分析,针对典型旋成体比较2种不同钝化外形(钝化半径均匀/非均匀)的气动性能.结果表明:在较小的钝化半径/高度下,由于前缘流向投影面积占整个旋成体流向投影面积比例较小,前缘气动性能对整个旋成体气动性能影响不大;但是,随着钝化半径/高度的增加,前缘气动性能对整个旋成体气动性能影响会逐渐增大.

关键词: 旋成体; 高超声速; 飞行器; 前缘; 气动力; CFD

中图分类号: V423.8;TB115.1文献标志码: B

Abstract: To study the effect of blunt shapes on the aerodynamic performance of hypersonic aircraft, based on CFD analysis, the aerodynamic performance of two different blunt shapes(the blunt radius are uniform or nonuniform) are compared for typical bodies of revolution. The results show that, under the smaller blunt radius/height, because the projection area in flow direction of leadingedge accounts for a small proportion of the projection area in flow direction of whole bodies of revolution, the leadingedge aerodynamic performance has a little effect on the aerodynamic performance of the whole bodies of revolution; however, with the increase of blunt radius/height, the effect of leadingedge aerodynamic performance on the aerodynamic performance of whole bodies of revolution increases gradually.

Key words: body of revolution; hypersonic speed; aircraft; leadingedge; aerodynamic force; CFD

引言

飞行器在高超声速飞行时,来流会对前缘产生较严重的气动热,而前缘驻点热流更严重.为改善这一情况,科学家针对驻点热流进行很多研究[19],结果均表明驻点热流与其驻点曲率半径的平方根成反比.采用较大的钝化半径可有效减小热流,但也会增强头部弓形激波,导致激波阻力急剧增加.文献[10]提出一种钝化半径非均匀的外形,基于数值模拟方法求解高超声速冻结流流场获得前缘热流分布,并应用遗传算法求解获得一个新外形(优化外形).结果表明,在相同的钝化半径/高度下,优化外形最大热流峰值比相应的圆弧钝化热流密度峰值减小大约20%.采用2种钝化外形时热流Q和压力P分布比较见图1和2,可以看出,优化前缘驻点附近热流较圆弧前缘有较明显下降,但同时压力分布也有较大差别,优化外形在驻点附近的压力明显高于圆弧钝化.优化外形较圆弧在防热方面有较大的优势,同时又会对气动力产生较大影响.为考察2种不同钝化外形对飞行器气动力性能的影响,针对高超声速旋成体,基于CFD数值模拟分析,开展2种不同钝化外形气动力性能的比较,分析不同钝化半径/高度在一定攻角变化范围内变化时对旋成体气动力性能的影响.

由图9可知:攻角在小范围内变化时,在相同的钝化外形下,升阻比随攻角的增大逐渐增大;在较小的钝化半径/高度下,优化外形的升阻比在相同的攻角下比圆弧外形的升阻比略低,但两者升阻比相差较小;随着钝化半径/高度的增加,由于阻力增加明显高于升力增加,两者升阻比差随攻角增大逐渐增大.

4结束语

通过对模型流场进行数值计算,得到优化外形钝化和圆弧钝化的流场,通过对2种不同钝化外形在不同钝化半径/高度下气动性能的分析,发现在较小的钝化半径/高度下,2种不同钝化外形对气动力性能影响不大,并且在小攻角范围内2种不同钝化外形对气动力性能影响也不大.随着钝化半径/高度的增大,2种不同钝化外形对气动力性能差别逐渐增大.

参考文献:

[1]REGINALD von DRIEST E. The problem of aerodynamic heating[J]. Aeronautical Eng Review, 1956, 15(10): 2641.

[2]LEES L. Laminar heat transfer over bluntnosed bodies at hypersonic flight speeds[J]. J Jet Propulsion, 1956, 26(4): 259269.

[3]FAY J A, RIDDELL F R. Theory of stagnation point heat transfer in dissociated air[J]. J Aeronautical Sci, 25, 1958, 25(1): 7385.

[4]KEMP N H, ROSE P H, DETRA R W. Laminar heat transfer around blunt bodies in dissociated air[J]. J Aeronautical Sci, 1959, 26(7): 421430.

[5]ROSE P H, STARK W. Stagnation point heat transfer measurements in dissociated air[J]. J Aeronautical Sci, 1958, 25(2): 8697.

[6]ROSE P H, STANKEVICS J O. Stagnation point heat transfer measurements in partially ionized air[J]. AIAA J, 1963, 1(12): 27522763.

[7]MARVIN J G, DEIWERT G S. Convective heat transfer in planetary gases[R]. Washington D C: NASA, 1965.

[8]SUTTON K, GRAVES R A. A general stagnationpoint convectiveheating equation for arbitrary gas mixtures[R]. Washington D C: NASA, 1971.

[9]ANDERSON J D. Hypersonic and high temperature gas dynamics[M]. Reston: AIAA, 2006.

[10]CUI K, HU S C. Shape design to minimize the peak heatflux of blunt leadingedge[C]//Proc 51st AIAA Aerospace Sci Meeting AIAA 20130233. Texas, 2013: 233259.(编辑武晓英)

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