摘要
在膨胀比ε=2～ 6、振荡管长径比L/d =10 7～ 73 0、射流激励频率 f =3 0～ 2 0 0Hz范围内 ,探讨了截面突扩型激波吸收器的消波效果及其对热分离器性能的影响 .结果表明 :在振荡管末端安装截面突扩短管可有效减弱管内反射激波强度 ,但当L/d≤ 10 7时则不能完全吸收反射激波 ;吸收管内反射激波 ,可提高制冷效率 ,降低最佳射流激励频率值 ,缩小热分离器体积及改善机器的变工况性能 .建立了在安装激波吸收器时振荡管参数间的最佳匹配关系 。
In the present paper, the reflected shock wave absorbing e ff ect and its influence on the performance of thermal separator are investigated b y means of a single-tube set-up.In the experiments, the shock wave absorber i s a short tube whose relative diameter D/d is 5.7 and relative length l/d is 9.0, the relative length of the oscillatory L/d is from 107 to 730. The expansion ratio is from 2.0 to 6.0 and the exciting frequency is from 30 t o 200 Hz. The experimental results show that the reflected shock wave is elimin ated effectively as L/d<400 while the absorber is mounted at the closed end of the tube, but when L/d>400, it makes no difference to mount the absorbe r anywhere because the energy of the reflected shock wave is exhausted by the vi scosity and friction of the gas inside the tube. Absorbing the reflected shoc k wave has great effect on the performance of thermal separator, e.g. the refrig eration efficiency is increased significantly, the optimal exciting frequency is decreased, the tube length can be shortened, the varying operating mode of the thermal separator can be improved, etc. When the tube is relatively short, the refrigeration efficiency is increased with the tube length, but when the tube le ngth is increased to some value, the result is just the contrary. The recommend ed optimal tube length L/d is 200-350 for the tube without absorber and 150 -250 for the tube with absorber. There exists a number of peak values of refri geration efficiency when the exciting frequency is increased and the optimal exc iting frequency is equal to the first, the second, and the third peak oscillator y frequency respectively when the tube length is L/d≤267, 267<L/d≤50 2, L/d>502. An optimal parameter matching relationship, which can be used to predict the value of the optimal exciting frequency, is derived in this paper .
出处
《化工学报》
EI
CAS
CSCD
北大核心
2003年第2期170-175,共6页
CIESC Journal
基金
国家自然科学基金 (No 5 92 762 49)
福建省自然科学基金(No E0 0 10 0 14 )
福建省教委基金 (No JA0 0 14 2 )资助项目~~
