20世纪初,人类学家伯特霍尔德·劳弗(Berthold Laufer, 1874—1934)参与“雅各布·希夫中国考察项目”(The Jacob Schiff China Expedition;1901-1904),三年间走遍中国东部,于上海、北京等地录制502枚蜡筒,内容包括戏曲、器乐...20世纪初,人类学家伯特霍尔德·劳弗(Berthold Laufer, 1874—1934)参与“雅各布·希夫中国考察项目”(The Jacob Schiff China Expedition;1901-1904),三年间走遍中国东部,于上海、北京等地录制502枚蜡筒,内容包括戏曲、器乐、民歌等音乐体裁,并计划将录音译谱出版。劳弗蜡筒目前多保存于美国传统音乐档案馆,2017年印第安纳大学采用尼古拉斯·伯格(Nicholas Bergh)设计的蜡筒播放系统,开始数字化工作。劳弗在录制一首作品时大多同时使用两台留声机分别撷取人声、乐声,然受限其时未有标准录制转速,故音频工程师需校准每组蜡筒音频的播放速度,匹配两份音档乐句位置,并平衡两台留声机马达出现的颤动现象,经修复后的音档出现了近似于立体声的音响效果。而劳弗蜡筒录音时间虽较穆麟德(Paul Georg von M9llendorff)晚,但后者录制内容为诗集朗诵。因此,劳弗蜡筒明确的音乐内容,乃目前已知最早于中国录制的音乐档案。展开更多
An experimental investigation is performed to assess the relation of interference performance on the total resistance of a pentamaran model advancing in calm water. For this motivation, the total drag of the ship is ...An experimental investigation is performed to assess the relation of interference performance on the total resistance of a pentamaran model advancing in calm water. For this motivation, the total drag of the ship is performed for several values of asymmetric outrigger configuration and hull separation, altering the Froude number in the range 0.3–0.9. Our results indicate that remarkable changes in resistance require notable changes in transverse distance values （hull separation） when wave interference may occur. In addition, there is no single configuration that consistently outperforms the other configurations across the entire speed range and the optimum interference factor -0.2 appears at a Froude number of 0.45 in S/L=0.33 with the outrigger outer position： asymmetric outboard for A3 configuration.展开更多
In this paper, towing tank experiments are conducted to study the behavior of flow on a model of the underwater vehicle with various shapes of bows, i.e. tango and standard bows in free surface motion tests. The total...In this paper, towing tank experiments are conducted to study the behavior of flow on a model of the underwater vehicle with various shapes of bows, i.e. tango and standard bows in free surface motion tests. The total resistances for different Froude numbers are considered experimentally. The towing tank is equipped with a trolley that can operate in through 0.05-6 m/s speed with ±0.02 m/s accuracy. Furthermore, the study is done on hydrodynamic coefficients i.e. total, residual and friction resistance coefficients, and the results are compared. Finally, the study on flow of wave fields around bows is done and wave filed around two bows are compared. The Froude number interval is between 0.099 and 0.349. Blockage fraction for the model is fixed to 0.005 3. The results showed that the residual resistance of the standard bow in 0.19 to 0.3 Froude number is more than the tango bow in surface motion which causes more total resistance for the submarine. Finally, details of wave generated by the bow are depicted and the effects of flow pattern on resistance drag are discussed.展开更多
This paper numerically investigates the influence of separation variation of the outriggers on the hydrodynamic performance of a high speed trimaran （HST） aiming at improving its applicability in diverse realistic d...This paper numerically investigates the influence of separation variation of the outriggers on the hydrodynamic performance of a high speed trimaran （HST） aiming at improving its applicability in diverse realistic disciplines. The present investigation was performed within the framework of the 2-D slender body method （SBM） by calculating the resistance of three symmetric trimaran series moving in a calm free surface of deep water. Each trimaran series comprises of 4681 configurations generated by considering 151 staggers （-50%≤a≤＋ 100%）, and 31 separations （100%≤β≤400%） for 81 Froude numbers （0.20≤Fn≤ 1.0）. In developing the three trimaran series, Wigley-st. AMECRC-09, and NPL-4a models were used separately for both the main and side hulls of each individu;d series models. A computer macro named Tri-PL was created using the Visual Basic for Applications~. Tri-PL~ sequentially interfaced Maxsurfe then Hullspeed to generate the models of the three trimaran series together with their detailed hydrostatic particulars, followed by their resistance components. The numerical results were partially validated against the available published numerical calculations and experimental results, to benchmark the Tri-PL macro and hence to rely on the analysis outcomes. A graph template was creaLed within the framework of SigmaPlot to visualize the significant results of the Tri-PL properlv.展开更多
文摘20世纪初,人类学家伯特霍尔德·劳弗(Berthold Laufer, 1874—1934)参与“雅各布·希夫中国考察项目”(The Jacob Schiff China Expedition;1901-1904),三年间走遍中国东部,于上海、北京等地录制502枚蜡筒,内容包括戏曲、器乐、民歌等音乐体裁,并计划将录音译谱出版。劳弗蜡筒目前多保存于美国传统音乐档案馆,2017年印第安纳大学采用尼古拉斯·伯格(Nicholas Bergh)设计的蜡筒播放系统,开始数字化工作。劳弗在录制一首作品时大多同时使用两台留声机分别撷取人声、乐声,然受限其时未有标准录制转速,故音频工程师需校准每组蜡筒音频的播放速度,匹配两份音档乐句位置,并平衡两台留声机马达出现的颤动现象,经修复后的音档出现了近似于立体声的音响效果。而劳弗蜡筒录音时间虽较穆麟德(Paul Georg von M9llendorff)晚,但后者录制内容为诗集朗诵。因此,劳弗蜡筒明确的音乐内容,乃目前已知最早于中国录制的音乐档案。
文摘An experimental investigation is performed to assess the relation of interference performance on the total resistance of a pentamaran model advancing in calm water. For this motivation, the total drag of the ship is performed for several values of asymmetric outrigger configuration and hull separation, altering the Froude number in the range 0.3–0.9. Our results indicate that remarkable changes in resistance require notable changes in transverse distance values （hull separation） when wave interference may occur. In addition, there is no single configuration that consistently outperforms the other configurations across the entire speed range and the optimum interference factor -0.2 appears at a Froude number of 0.45 in S/L=0.33 with the outrigger outer position： asymmetric outboard for A3 configuration.
文摘In this paper, towing tank experiments are conducted to study the behavior of flow on a model of the underwater vehicle with various shapes of bows, i.e. tango and standard bows in free surface motion tests. The total resistances for different Froude numbers are considered experimentally. The towing tank is equipped with a trolley that can operate in through 0.05-6 m/s speed with ±0.02 m/s accuracy. Furthermore, the study is done on hydrodynamic coefficients i.e. total, residual and friction resistance coefficients, and the results are compared. Finally, the study on flow of wave fields around bows is done and wave filed around two bows are compared. The Froude number interval is between 0.099 and 0.349. Blockage fraction for the model is fixed to 0.005 3. The results showed that the residual resistance of the standard bow in 0.19 to 0.3 Froude number is more than the tango bow in surface motion which causes more total resistance for the submarine. Finally, details of wave generated by the bow are depicted and the effects of flow pattern on resistance drag are discussed.
文摘This paper numerically investigates the influence of separation variation of the outriggers on the hydrodynamic performance of a high speed trimaran （HST） aiming at improving its applicability in diverse realistic disciplines. The present investigation was performed within the framework of the 2-D slender body method （SBM） by calculating the resistance of three symmetric trimaran series moving in a calm free surface of deep water. Each trimaran series comprises of 4681 configurations generated by considering 151 staggers （-50%≤a≤＋ 100%）, and 31 separations （100%≤β≤400%） for 81 Froude numbers （0.20≤Fn≤ 1.0）. In developing the three trimaran series, Wigley-st. AMECRC-09, and NPL-4a models were used separately for both the main and side hulls of each individu;d series models. A computer macro named Tri-PL was created using the Visual Basic for Applications~. Tri-PL~ sequentially interfaced Maxsurfe then Hullspeed to generate the models of the three trimaran series together with their detailed hydrostatic particulars, followed by their resistance components. The numerical results were partially validated against the available published numerical calculations and experimental results, to benchmark the Tri-PL macro and hence to rely on the analysis outcomes. A graph template was creaLed within the framework of SigmaPlot to visualize the significant results of the Tri-PL properlv.
