In the study, the influence of cell tilting on flow dynamics is explored experimentally in a rectangular cell (aspect ratios Gamma(x) = 1 and Gamma(y) = 0.25 ). The measurements are carried out in a wide range of tilt angles (0 <= beta <= pi/2 rad) at Prandtl number (Pr similar or equal to 6.3 ) and Rayleigh number (Ra similar or equal to 4.42 x 10(9) ). With the velocity measurements, the large-scale circulation (LSC) is found to be sensitive to the symmetry of the system. In the level case, the LSC is at about quarter width of the cell. As the cell is slightly tilted (beta similar or equal to 0.04 rad), the LSC moves quickly towards the boundary. With increasing beta , the LSC changes gradually from oblique ellipse-like to square-like, and to more complicated patterns. Oscillation has been found for almost all beta, and are strongest at around beta similar or equal to 0.48 rad. As beta increases, the Reynolds number (Re) initially also increases, until it reaches its maximum at the transition angle beta = 0 .15 rad, after which it gradually decreases. The cell tilting causes a pronounced reduction of the Nusselt number (Nu). As beta increases from 0 to 0.15, 1.05 and pi/2 rad, the reduction of Nu is approximately 1.4 %, 5% and 18 %, respectively. Over the ranges of 0 <= beta <= 0.15 rad, 0.15 <= beta <= 1.05 rad and 1.05 <= beta <= pi/2 rad, the decay slopes are 8.57 x 10 (2), 3.27 x 10 (2) and 0.24 rad (-1), respectively.
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机译：在这项研究中，实验研究了矩形单元格（纵横比Gamma（x）= 1和Gamma（y）= 0.25）中单元倾斜对流动动力学的影响。在Prandtl数（Pr等于或等于6.3）和Rayleigh数（Ra等于或等于4.42 x 10（9））的大倾角范围（0 <= beta <= pi / 2 rad）中进行测量）。通过速度测量，发现大规模循环（LSC）对系统的对称性敏感。在水平情况下，LSC大约为像元的四分之一宽度。随着像元稍微倾斜（β相似或等于0.04 rad），LSC迅速移向边界。随着beta的增加，LSC逐渐从斜椭圆形变为方形，并变为更复杂的模式。已经发现几乎所有β都存在振荡，并且在β相似或等于0.48 rad时最强。随着β的增加，雷诺数（Re）最初也会增加，直到在过渡角β= 0.15 rad处达到最大值，此后逐渐减小。单元倾斜会导致Nusselt值（Nu）显着降低。当β从0增加到0.15、1.05和pi / 2 rad时，Nu的减少分别约为1.4％，5％和18％。在0 <= beta <= 0.15 rad，0.15 <= beta <= 1.05 rad和1.05 <= beta <= pi / 2 rad的范围内，衰减斜率分别为8.57 x 10（2），3.27 x 10（2）和0.24 rad（-1）。
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