载人飞船返回舱着水冲击问题研究进展

通过归纳一般物体入水冲击问题解析法和数值法的种类和发展,对载人飞船返回舱着水冲击问题进行了应用研究;重点对国内外工程上进行的返回舱着水实验进行了整理,并根据实验舱体的复杂程度将其分为模型实验和样机实验两类,指出分别使用刚性缩比模型、弹性缩比模型和样机进行着水实验时,成本、实验周期及其结果数据丰富程度递增的特点,指出了需要注意的弹性近似准确性和样机在不同实验工况下的适应性改造问题：同时对近年来研究较多的返回舱着水冲击问题的仿真分析方法进行了总结对比,讨论了其适用于任意舱体外形、任意姿态着水问题分析以及能够获得全过程详细动力学特性的优势。     

发动机进气道短舱前缘结冰三维模拟研究

为计算发动机进气道短舱前缘的结冰冰形,在Messinger结冰热力学模型的基础上发展了一套纯三维的表面溢流水流动结冰模型。考虑空气摩擦力为表面溢流水流动的主要驱动力,用空气对进气道表面的剪切力来确定溢流水的流动方向及流量分配。为求解溢流水结冰模型,发展了一套重复查找表面控制体状态的方法,能够快速完成整个三维表面的计算。用该方法对某三维发动机进气道进行计算,得到了三维结冰冰形,并将计算结果与FENSAP-ICE计算结果进行了对比,结果显示两者的冰形轮廓基本一致,仅在冰角处存在差异,表明本文三维发动机结冰计算模型与计算方法是有效的,其计算精度与FENSAP-ICE结果相当。     

Investigation of thermal protection system by forward-facing cavity and opposing jet combinatorial configuration

 This paper focuses on the usage of the forward-facing cavity and opposing jet combinatorial configuration as the thermal protection system (TPS) for hypersonic vehicles. A hemispherecone nose-tip with the combinatorial configuration is investigated numerically in hypersonic free stream. Some numerical results are validated by experiments. The flow field parameters, aerodynamic force and surface heat flux distribution are obtained. The influence of the opposing jet stagnation pressure on cooling efficiency of the combinatorial TPS is discussed. The detailed numerical results show that the aerodynamic heating is reduced remarkably by the combinatorial system. The recirculation region plays a pivotal role for the reduction of heat flux. The larger the stagnation pressure of opposing jet is, the more the heating reduction is. This kind of combinatorial system is suitable to be the TPS for the high-speed vehicles which need long-range and long time flight.     

Locating Current Sheets in the Solar Corona

Current sheets are essential for energy dissipation in the solar corona, in particular by enabling magnetic reconnection. Unfortunately, sufficiently thin current sheets cannot be resolved observationally and the theory of their formation is an unresolved issue as well. We consider two predictors of coronal current concentrations, both based on geometrical or even topological properties of a force-free coronal magnetic field. First, there are separatrices related to magnetic nulls. Through separatrices the magnetic connectivity changes discontinuously. Coronal magnetic nulls are, however, very rare. Second, inspired by the concept of generalized magnetic reconnection without nulls, quasi-separatrix layers (QSL) were suggested. Through QSL the magnetic connectivity changes continuously, though strongly. The strength of the connectivity change can be quantified by measuring the squashing of the flux tubes which connect the magnetically conjugated photospheres. We verify the QSL and separatrix concepts by comparing the sites of magnetic nulls and enhanced squashing with the location of current concentrations in the corona. Due to the known difficulties of their direct observation, we simulated coronal current sheets by numerically calculating the response of the corona to energy input from the photosphere, heating a simultaneously observed Extreme Ultraviolet Bright Point. We did not find coronal current sheets at separatrices but at several QSL locations. The reason is that, although the geometrical properties of force-free extrapolated magnetic fields can indeed hint at possible current concentrations, a necessary condition for current sheet formation is the local energy input into the corona.     

飞机电动机过热研究

首先从飞机防火角度，用对称分量法分析了航空电机在不对称电源下的发热情况，推导了发热电流的公式，以此作为数学模型，解释缺相时电机很快烧毁的物理现象。最后提出了防止航空三相电动机过热与起火的方法，包括采用电机在线状态监控、主动维护、增加有效的保护装置等。     

集中供暖住宅分户热计量系统设计分折

从主立管系统和室内管线系统两个方面介绍分户热计量系统的几种设计形式，并分析每种形式优缺点，同时指出了阀门、热表等附件设计安装要点。     

Revealing the hot intergalactic medium with ROSAT

The X-ray background intensity around galaxies and rich clusters of galaxies is investigated in three energy bands using the ROSAT All-Sky Survey maps. It is found that an amplitude of the XRB enhancements surrounding the Abell clusters and high density areas in the Lick galaxy counts depends on photon energy. Excess flux generated in the surrounding of the galaxy concentrations is consistent with the thermal emission by hot gas postulated by hydrodynamic simulations.     

Theoretical aerothermal concepts for configuration design of hypersonic vehicles

Convection coefficients and heat fluxes due to aerodynamic heating on critical surfaces of hypersonic vehicle are obtained analytically. The applicability of recovery temperature for stagnation regions is discussed. Convection coefficient for the bicurvature forward stagnation region is obtained directly from 2-D stagnation region correlation, using the two principal radii of curvatures. Convective heat flux to swept-back leading edge (SBLE) surface is obtained from the 2-D stagnation region and flat plate heat fluxes, using the respective velocity vector components. Results reveal the concepts of temperature-minimised-sweepback, and the thermally-benign sharp SBLE effect at high sweepback angles.     

Estimation of vertically integrated water vapor in Hungary using MODIS imagery

Information about the amount and spatial structure of atmospheric water vapor is essential in understanding meteorology and the Earth environment. Space-borne remote sensing offers a relatively inexpensive method to estimate atmospheric water vapor in the form of integrated water vapor (IWV). The research activity reported in the present paper is based on the data acquired by the HRPT/MODIS (High Resolution Picture Transmission, MODerate resolution Imaging Spectroradiometer) receiving station established in Budapest (Hungary) by the Space Research Group of the Eötvös Loránd University. Integrated water vapor is estimated by the remotely sensed data of the MODIS instrument with different methods and also by the operational numerical weather prediction model of the European Centre for Medium-Range Weather Forecasts (ECMWF). Radiosonde data are used to evaluate the accuracy of the different IWV fields though it has been pointed out that the in situ data also suffers from uncertainties. It was found that both the MODIS and the ECMWF based fields are of good accuracy. The satellite data represent finer scale spatial structures while the ECMWF data have a relatively poor spatial resolution. The high quality IWV fields have proved to be useful for radiative transfer studies such as the atmospheric correction of other satellite data from times different than the overpass times of satellites Terra/Aqua and the forecast times of the model data. For this purpose the temporal variability of IWV is scrutinized both using ECMWF and MODIS data. Taking advantage of Terra and Aqua overpasses, the mean rate of change of IWV estimated by the near infrared method was found to be 0.47 ± 0.45 kg m⁻² h⁻¹, while it was 0.13 ± 0.65 kg m⁻² h⁻¹ based on the infrared method. The numerical weather prediction model’s analysis data estimated −0.01 ± 0.13 kg m⁻² h⁻¹ for the mean growth rate, while using forecast data it was 0.24 ± 0.18 kg m⁻² h⁻¹. MODIS data should be used when available for the estimation of the IWV in other studies. If no satellite data are available, or available data are only from one overpass, ECMWF based IWV can be used. In this case the analysis fields (or the satellite field) should be used for temporal extrapolation but the rate of change should be calculated from the forecast data due to its higher temporal resolution.     

钨板加热旋压模具设计及加热方法研究

本文主要论述纯钨板成形时模具及靠板的设计、调试，并对成形过程中模具及钨板的加热方法、工艺参数进行了分析。