1.27 μm波段的氧分子近红外气辉是火星大气最重要的气辉辐射之一, 该气辉高光谱分辨辐射传输模型的建立对于研制火星探测载荷, 反演火星大气的风场温度场与臭氧浓度, 以及研究火星空间物理, 有重要的科学价值与工程意义.在研究火星大气O2(a1Δg)气辉光化学反应模型的基础上, 提出了O2(a1Δg)气辉体辐射率的计算方法, 并建立了火星大气气辉辐射传输理论; 通过与用于研究火星大气特征的光谱学探测仪(Spectroscopy Spectrograph for the Investigation of Characteristics of the Atmosphere of Mars, SPICAM)的实测数据进行对比, 验证了所建立的火星O2(a1Δg)气辉高光谱分辨辐射传输模型的准确性; 针对火星与地球大气的O2(a1Δg)气辉, 在体辐射率、自吸收效应, 以及临边辐射光谱特性三个方面进行了系统深入的比较, 对比结果表明, 火星大气由于密度低、氧气丰度小, 其自吸收效应可以忽略不计, 但其O2(a1Δg)气辉辐射强度与地球大气相当, 可以用于火星大气的风场温度场与臭氧浓度的探测与反演.
A Navier–Stokes solver is used to examine steep waves as they run up a steep beach (10.54°). The volume of fluid method (VOF) is used to model the free surface. Comparison with experimental results shows reasonable overall agreement in the prediction of the free-surface, velocities and accelerations within the flow. A spurious feature at the free-surface was found which does reduce the quality of the results. For a steep wave we see the transition from a steep wave front to a smooth run-up tongue at the beach that is in qualitative agreement with experiment. 相似文献
Pressure variations and three-dimensional effects on liquid sloshing loads in a moving partially filled rectangular tank have been carried out numerically and experimentally. A numerical algorithm based on the volume of fluid (VOF) technique is used to study the non-linear behavior and damping characteristics of liquid sloshing. A moving coordinate system is used to include the non-linearity and avoid the complex boundary conditions of moving walls. The numerical model solves the complete Navier–Stokes equations in primitive variables by using of the finite difference approximations. In order to mitigate a series of discrete impacts, the signal computed is averaged over several time steps. In order to assess the accuracy of the method used, computations are compared with the experimental results. Several configurations of both baffled and unbaffled tanks are studied. Comparisons show good agreement for both impact and non- impact type slosh loads in the cases investigated. 相似文献
The International Nusantara Stratification and Transport (INSTANT) program measured currents through multiple Indonesian Seas passages simultaneously over a three-year period (from January 2004 to December 2006). The Indonesian Seas region has presented numerous challenges for numerical modelers — the Indonesian Throughflow (ITF) must pass over shallow sills, into deep basins, and through narrow constrictions on its way from the Pacific to the Indian Ocean. As an important region in the global climate puzzle, a number of models have been used to try and best simulate this throughflow. In an attempt to validate our model, we present a comparison between the transports calculated from our model and those calculated from the INSTANT in situ measurements at five passages within the Indonesian Seas (Labani Channel, Lifamatola Passage, Lombok Strait, Ombai Strait, and Timor Passage). Our Princeton Ocean Model (POM) based regional Indonesian Seas model was originally developed to analyze the influence of bottom topography on the temperature and salinity distributions in the Indonesian seas region, to disclose the path of the South Pacific Water from the continuation of the New Guinea Coastal Current entering the region of interest up to the Lifamatola Passage, and to assess the role of the pressure head in driving the ITF and in determining its total transport. Previous studies found that this model reasonably represents the general long-term flow (seasons) through this region. The INSTANT transports were compared to the results of this regional model over multiple timescales. Overall trends are somewhat represented but changes on timescales shorter than seasonal (three months) and longer than annual were not considered in our model. Normal velocities through each passage during every season are plotted. Daily volume transports and transport-weighted temperature and salinity are plotted and seasonal averages are tabulated. 相似文献