本文選題：下降過(guò)程 + 流固耦合��； 參考：《航天返回與遙感》2016年03期

【摘要】：隨著計(jì)算機(jī)技術(shù)的不斷發(fā)展以及數(shù)值模擬技術(shù)的興起,對(duì)降落傘力學(xué)特性的模擬日益精確。為了消除傳統(tǒng)降落傘模擬中因網(wǎng)格大變形而產(chǎn)生負(fù)體積的影響,文章采用光滑粒子流體動(dòng)力學(xué)方法,對(duì)選定降落傘模型開展了穩(wěn)降階段的流固耦合數(shù)值模擬,計(jì)算得到的氣動(dòng)力系數(shù)與風(fēng)洞試驗(yàn)結(jié)果較為一致。研究了空氣粒子密度對(duì)數(shù)值結(jié)果的影響,結(jié)果表明,粒子密度過(guò)少,降落傘結(jié)構(gòu)單元難以和流場(chǎng)實(shí)現(xiàn)有效耦合,計(jì)算精度降低;但粒子密度超過(guò)一定值,不僅會(huì)增加計(jì)算消耗,也會(huì)增加舍入誤差而影響計(jì)算精度,確定了最佳粒子數(shù)。在此基礎(chǔ)上,模擬了不同初速度下降落傘的下降過(guò)程,獲得了降落傘外形、投影直徑、下降速度、降落傘氣動(dòng)力及傘衣擺角的動(dòng)態(tài)變化情況。數(shù)值結(jié)果表明傘衣的呼吸頻率、穩(wěn)定后的平衡速度和氣動(dòng)力受速度影響較小,但速度增加,傘衣呼吸強(qiáng)度及擺角增加,且擺動(dòng)角度的衰減性要低于投影直徑的衰減能力。SPH模擬方法有效地回避了降落傘流固耦合的網(wǎng)格大變形問(wèn)題,在柔性大變形流固耦合問(wèn)題上有廣闊的應(yīng)用前景。
[Abstract]:With the development of computer technology and the rise of numerical simulation technology, the simulation of parachute mechanical characteristics is becoming more and more accurate. In order to eliminate the negative volume effect caused by large mesh deformation in the traditional parachute simulation, the fluid-solid coupling numerical simulation of the selected parachute model is carried out by using the smooth particle hydrodynamics method. The calculated aerodynamic coefficients are in good agreement with the wind tunnel test results. The effect of air particle density on the numerical results is studied. The results show that if the particle density is too small, it is difficult for parachute structure elements to be effectively coupled with the flow field, and the calculation accuracy is reduced, but if the particle density exceeds a certain value, the computational consumption will not only increase. The rounding error will also affect the accuracy of the calculation and determine the optimum number of particles. On this basis, the descent process of parachute at different initial velocities is simulated, and the dynamic changes of parachute shape, projection diameter, descent velocity, parachute aerodynamic force and yaw angle of parachute coat are obtained. The numerical results show that the respiration frequency, equilibrium velocity and aerodynamic force of the canopy are less affected by the velocity, but the velocity increases, and the respiration intensity and swing angle increase. Moreover, the attenuation of swing angle is lower than that of projection diameter. SPH simulation method effectively avoids the problem of large grid deformation of parachute fluid-solid coupling, and has a broad application prospect in flexible large deformation fluid-solid coupling problem.
【作者單位】： 南京航空航天大學(xué)航空宇航學(xué)院;
【基金】：國(guó)家自然科學(xué)基金(11172137)資助項(xiàng)目 江蘇高校優(yōu)勢(shì)學(xué)科建設(shè)工程資助項(xiàng)目(PAPD) 南京航空航天大學(xué)研究生創(chuàng)新基地(實(shí)驗(yàn)室)開放基金資助(kfjj20150104-01) 中央高校基本科研業(yè)務(wù)費(fèi)專項(xiàng)資金資助
【分類號(hào)】：V445.23
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本文編號(hào)：1873396