计算物理
計算物理
계산물리
CHINESE JOURNAL OF COMPUTATIONAL PHYSICS
2001年
1期
10-16
,共7页
剪切层%激波%卷吸涡%扩散混合%数值计算
剪切層%激波%捲吸渦%擴散混閤%數值計算
전절층%격파%권흡와%확산혼합%수치계산
用迎风TVD格式求解二维、层流全N-S方程,对激波沿H2和空气界面绕圆、方柱流动及其诱导的剪切混合进行了数值模拟,得到了流场的压力和组分密度分布.计算结果表明:激波在H2传播得快,剪切层中出现卷吸涡和调节激波.卷吸涡与柱体撞击后,反射出一道激波,H2沿柱体表面向下游扩散.H2/空气接触面与柱体分离后,形状畸变并产生新的卷吸涡.H2分布表明:在界面上加圆柱或方柱,可有效地强化燃料混合,方柱的增强效果更明显些.在圆柱表面,H2、空气中激波均发生由RR向MR的转变,两Mach杆在下游相互透射.对于方柱,H2中激波沿下表面传播几乎不受影响,空气中激波沿上表面发生Mach反射,其Mach杆和H2中绕射激波相互透射.柱体左侧最终形成一脱体激波,流场存在激波、卷吸涡、接触面间的相互作用,但波系结构相似.
用迎風TVD格式求解二維、層流全N-S方程,對激波沿H2和空氣界麵繞圓、方柱流動及其誘導的剪切混閤進行瞭數值模擬,得到瞭流場的壓力和組分密度分佈.計算結果錶明:激波在H2傳播得快,剪切層中齣現捲吸渦和調節激波.捲吸渦與柱體撞擊後,反射齣一道激波,H2沿柱體錶麵嚮下遊擴散.H2/空氣接觸麵與柱體分離後,形狀畸變併產生新的捲吸渦.H2分佈錶明:在界麵上加圓柱或方柱,可有效地彊化燃料混閤,方柱的增彊效果更明顯些.在圓柱錶麵,H2、空氣中激波均髮生由RR嚮MR的轉變,兩Mach桿在下遊相互透射.對于方柱,H2中激波沿下錶麵傳播幾乎不受影響,空氣中激波沿上錶麵髮生Mach反射,其Mach桿和H2中繞射激波相互透射.柱體左側最終形成一脫體激波,流場存在激波、捲吸渦、接觸麵間的相互作用,但波繫結構相似.
용영풍TVD격식구해이유、층류전N-S방정,대격파연H2화공기계면요원、방주류동급기유도적전절혼합진행료수치모의,득도료류장적압력화조분밀도분포.계산결과표명:격파재H2전파득쾌,전절층중출현권흡와화조절격파.권흡와여주체당격후,반사출일도격파,H2연주체표면향하유확산.H2/공기접촉면여주체분리후,형상기변병산생신적권흡와.H2분포표명:재계면상가원주혹방주,가유효지강화연료혼합,방주적증강효과경명현사.재원주표면,H2、공기중격파균발생유RR향MR적전변,량Mach간재하유상호투사.대우방주,H2중격파연하표면전파궤호불수영향,공기중격파연상표면발생Mach반사,기Mach간화H2중요사격파상호투사.주체좌측최종형성일탈체격파,류장존재격파、권흡와、접촉면간적상호작용,단파계결구상사.
Upwind TVD scheme is used to solve laminar, 2D fully N-Sequations. A shock diffracted by a cylinder or square cylinder along hydrogen air interface, and mixing enhancement in a shear flow are numerically studied. The results indicate that the shock travels faster in hydrogen. An adjustable shock and a swirling ovrtex appear in the shear region. After the swirling vortex impacts the cylinders, a reflected shock is formed, and hydrogen diffuses downstream in the region near cylinder walls. Contact surfaces are deformed and another vortex is generated. The distribution of hydrogen shows that the mixing is enhanced effectively by inserting cylinders along the interface, expecially for a square cylinder. The transition from RR to MR can be found for shocks traveling both in air and in hydrogen for a cylinder. Two Mach stems will transmit each other at the downstream. But in the case of a square column, the shock is almost not affected along the lower wall but Mach reflection takes place along the upper wall, then a diffracted shock and a Mach stem transmit each other finally. For both cases, the detached shock occurs on the right of cylinders. Similar shock structures arise, and contributions of cylinder shape are eventually forgotten.