李華鵬,朱秀麗,李鵬松,袁洪君
(1. 東北電力大學(xué) 理學(xué)院,吉林 吉林 132012; 2. 吉林大學(xué) 數(shù)學(xué)學(xué)院,長春 130012)
一類可壓縮非牛頓流解的爆破準(zhǔn)則
李華鵬1,朱秀麗1,李鵬松1,袁洪君2
(1. 東北電力大學(xué) 理學(xué)院,吉林 吉林 132012; 2. 吉林大學(xué) 數(shù)學(xué)學(xué)院,長春 130012)
利用反證法研究一類真空可壓縮非牛頓流體,給出了其強(qiáng)解的爆破準(zhǔn)則. 即當(dāng)時間t趨于臨界時間T*時,若速度的導(dǎo)數(shù)是有界的,則該局部強(qiáng)解關(guān)于時間可以延拓成整體解. 特別地,允許初始密度含有真空的情形.
爆破準(zhǔn)則; 可壓縮非牛頓流體; 真空; 強(qiáng)解
考慮一類可壓縮非牛頓流體方程:
帶有初邊值條件
其中:p>2,μ0>0是給定的正常數(shù);ΩT=I×(0,T),I=(0,1); (ρ0,u0)為已知函數(shù),滿足
非牛頓流體應(yīng)用廣泛,如石油、 泥漿、 油漆以及人體的血液、 淋巴液等都屬于非牛頓流體. 目前,關(guān)于可壓縮非牛頓流體方程解的研究已取得一些成果,例如: 文獻(xiàn)[1]研究了一類具線性阻尼和真空的可壓縮非牛頓流強(qiáng)解的存在唯一性; 文獻(xiàn)[2]研究了一類可壓縮剪切變稠流速度的有限傳播性質(zhì)及其強(qiáng)解的存在唯一性; 文獻(xiàn)[3]研究了一類非牛頓流體小初值整體強(qiáng)解的存在唯一性. 關(guān)于爆破準(zhǔn)則的研究可參見文獻(xiàn)[4-7]. 本文研究非牛頓流體數(shù)學(xué)模型強(qiáng)解的爆破準(zhǔn)則問題.
先給出問題(1)-(2)強(qiáng)解的局部存在性[8]結(jié)論.
證明思路: 利用反證法,假設(shè)
(5)
在方程(1)1兩端同時乘pρp-1(p≥γ)并在I上積分,利用標(biāo)準(zhǔn)能量估計可得密度ρ的L∞估計.
將式(1)1代入式(1)2中,并對所得方程關(guān)于t求導(dǎo),在兩端同時乘以ut后再積分,利用引理1和引理2及Gronwall’s不等式,易得:
利用方程組(1)及前述引理,易得如下二階估計.
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(責(zé)任編輯: 趙立芹)
Blow-upCriterionforaClassofCompressibleNon-NewtonianFluidswithVacuum
LI Huapeng1,ZHU Xiuli1,LI Pengsong1,YUAN Hongjun2
(1.CollegeofScience,NortheastDianliUniversity,Jilin132012,JilinProvince,China;
2.CollegeofMathematics,JilinUniversity,Changchun130012,China)
We obtained a blow-up criterion for strong solutions to a class of compressible non-Newtonian fluids just in terms of the derivative of the velocity using the proof of contradiction. In other words,if the derivative of the velocity remains bounded as timetapproaches to the critical time,a local strong solution can be continued globally in time. In addition,the initial vacuum states are allowed in our cases.
blow-up criterion; compressible non-Newtonian fluids; vacuum; strong solutions
2014-06-26.
李華鵬(1984—),男,漢族,博士,講師,從事偏微分方程的研究,E-mail: huapeng.li@163.com.
國家自然科學(xué)基金(批準(zhǔn)號: 11271153)、 博士點(diǎn)基金(批準(zhǔn)號: 20140101-20161231)、 吉林省科技發(fā)展計劃項(xiàng)目(批準(zhǔn)號: 20130101065JC)和東北電力大學(xué)博士科研啟動基金(批準(zhǔn)號: BSJXM-201331).
O175.2
A
1671-5489(2014)05-0969-02