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Sidewall temperature PDFs, r/R = 1, for z/H = 1/4 (diamonds), z/H = 1/2 (circles), and z/H = 3/4 (squares), with 1/Ro = 0 (a, c) and 10 (b, d). Experimental measurements with Ra = 8 × 10 12 (a, b) and DNS with Ra = 10 9 (c, d), both with Pr = 0.8. Bimodal Gaussian distributions (solid lines), the sum of two normal distributions (dashed lines), are observed for rapid rotation (b, d). ··z s denotes average in time and over all sensor positions at distance z from the hot plate.
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For rapidly rotating turbulent Rayleigh--B\'enard convection in a slender cylindrical cell, experiments and direct numerical simulations reveal a boundary zonal flow (BZF) that replaces the classical large-scale circulation. The BZF is located near the vertical side wall and enables enhanced heat transport there. Although the azimuthal velocity of...
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... technique for parameterizing the LSC in RBC [18,20,[36][37][38]. We measured experimentally and in corresponding DNS the temperature at 8 equidistantly spaced azimuthal locations of the sensors for each of 3 distances from the bottom plate: z/H = 1/4, 1/2 and 3/4. The PDFs of the experimental data without rotation (1/Ro = 0, Ra = 8 × 10 12 ) in Fig. 1a show a distribution with a single peak and slight asymmetry to hotter (colder) fluctuations for heights smaller (larger) than z/H = 1/2, whereas the PDFs for rapid rotation (1/Ro = 10, Fig. 1b), show a bimodal distribution that is well fit by the sum of two Gaussian distributions. The corresponding PDFs of the DNS data (at Ra = 10 9 ) ...
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... for each of 3 distances from the bottom plate: z/H = 1/4, 1/2 and 3/4. The PDFs of the experimental data without rotation (1/Ro = 0, Ra = 8 × 10 12 ) in Fig. 1a show a distribution with a single peak and slight asymmetry to hotter (colder) fluctuations for heights smaller (larger) than z/H = 1/2, whereas the PDFs for rapid rotation (1/Ro = 10, Fig. 1b), show a bimodal distribution that is well fit by the sum of two Gaussian distributions. The corresponding PDFs of the DNS data (at Ra = 10 9 ) show the same qualitative transition from a single peak without rotation to a bimodal distribution in the rapidly rotating case with similar hot/cold asymmetry for different z (Fig. 1c, d). To ...
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... rotation (1/Ro = 10, Fig. 1b), show a bimodal distribution that is well fit by the sum of two Gaussian distributions. The corresponding PDFs of the DNS data (at Ra = 10 9 ) show the same qualitative transition from a single peak without rotation to a bimodal distribution in the rapidly rotating case with similar hot/cold asymmetry for different z (Fig. 1c, d). To understand the nature of the emergence of a bimodal distribution near the radial boundary, we consider the DNS data in ...
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... technique for parameterizing the LSC in RBC [18,20,[36][37][38]. We measured experimentally and in corresponding DNS the temperature at 8 equidistantly spaced azimuthal locations of the sensors for each of 3 distances from the bottom plate: z/H = 1/4, 1/2 and 3/4. The PDFs of the experimental data without rotation (1/Ro = 0, Ra = 8 × 10 12 ) in Fig. 1a show a distribution with a single peak and slight asymmetry to hotter (colder) fluctuations for heights smaller (larger) than z/H = 1/2, whereas the PDFs for rapid rotation (1/Ro = 10, Fig. 1b), show a bimodal distribution that is well fit by the sum of two Gaussian distributions. The corresponding PDFs of the DNS data (at Ra = 10 9 ) ...
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... for each of 3 distances from the bottom plate: z/H = 1/4, 1/2 and 3/4. The PDFs of the experimental data without rotation (1/Ro = 0, Ra = 8 × 10 12 ) in Fig. 1a show a distribution with a single peak and slight asymmetry to hotter (colder) fluctuations for heights smaller (larger) than z/H = 1/2, whereas the PDFs for rapid rotation (1/Ro = 10, Fig. 1b), show a bimodal distribution that is well fit by the sum of two Gaussian distributions. The corresponding PDFs of the DNS data (at Ra = 10 9 ) show the same qualitative transition from a single peak without rotation to a bimodal distribution in the rapidly rotating case with similar hot/cold asymmetry for different z (Fig. 1c, d). To ...
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... rotation (1/Ro = 10, Fig. 1b), show a bimodal distribution that is well fit by the sum of two Gaussian distributions. The corresponding PDFs of the DNS data (at Ra = 10 9 ) show the same qualitative transition from a single peak without rotation to a bimodal distribution in the rapidly rotating case with similar hot/cold asymmetry for different z (Fig. 1c, d). To understand the nature of the emergence of a bimodal distribution near the radial boundary, we consider the DNS data in ...
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