应用喉声气流图对腭裂患者发声强度的初步观察

本文应用SH—01型喉声气流图仪对23名腭裂术前后患者及11名正常人发“啊”(a:)、“衣”(i:)捏鼻及不捏鼻时发声强度进行检测,结果显示:腭裂患者不同发音之间发声强度的差别具有显著或非常显著意义;同一发音捏鼻与不捏鼻之间发声强度的差别在发a:音时无显著意义(P>0.05),在发i:音时有显著意义(P<0.05);不同腭裂患者间发声强度的差别具有非常显著意义(P<0.001)。正常对照组不同发音时发声强度的差别无显著意义(P>0.05)。而不同人之间差别具有非常显著意义(P<0.01)。故作者认为:腭裂患者由于腭咽闭合不全以及形成的不良发音习惯,对患者发音强度有不同的影响,从而使其语音不清及出现过高鼻音。不同患者及正常人之间发声强度的差别尚待进一步探讨。

中老年正常人发音“i:”时呼气流量、声强、基频及其相互关系的研究

本文应用喉音气流仪对120名(40～69岁)男女进行了舒适平稳发“i:”音的检测。结论:1.初步确定了男女发“i:”音时呼气流量、声强、基频的正常范围,男女在基频上有显著差异;2.男女发“i:”音时基频的平均瞬时变化率在0.0～0.3%之间;3.确定了发音效率的评价方法;4.男女最长声时随年龄增长而缩短;5.提出了用呼气流量与肺活量之比评价唯功能的优劣。

PIV MEASUREMENT FOR SWIRLER FLOW FIELD IN GAS TURBINE COMBUSTOR

The characteristics of swirler flow field, including cold flow field and combustion flow field, in gas tur- bine combustor with two-stage swirler are studied by using particle image velocimetry （PIV）. Velocity compo- nents, fluctuation velocity, Reynolds stress and recirculation zone length are obtained, respectively. Influences of geometric parameter of primary hole, arrangement of primary hole, inlet air temperature, first-stage swirler an- gle and fuel/air ratio on flow field are investigated, respectively. The experimental results reveal that the primary recirculation zone lengths of combustion flow field are shorter than those of cold flow field, and the primary reeir- culation zone lengths decrease with the increase of inlet air temperature and fuel/air ratio. The change of the geo- metric parameter of primary hole casts an important influence on the swirler flow field in two-stage swirler com- bustor.

关于FPMC-4.88万吨成品油/化学品船舱室作业通风优化探讨

本文通过对公司在建船舶FPMC-4.88万吨成品油/化学品船船坞建造阶段各个区域舱室的通风布置进行探讨、分析,对其存在的问题进行优化方案,为公司建造后续船舶在通风布置上提供借鉴。

Turbulent Characteristic of Liquid Around a Chain of Bubbles in Non-Newtonian Fluid

The turbulence behavior of gas-liquid two-phase flow plays an important role in heat transfer and mass transfer in many chemical processes. In this work, a 2D particle image velocimetry (PIV) was used to investigate the turbulent characteristic of fluid induced by a chain of bubbles rising in Newtonian and non-Newtonian fluids. The instantaneous flow field, turbulent kinetic energy (TKE) and TKE dissipation rate were measured. The results demonstrated that the TKE profiles were almost symmetrical along the column center and showed higher values in the central region of the column. The TKE was enhanced with the increase of gas flow and decrease of liquid viscosity. The maximum TKE dissipation rate appeared on both sides of the bubble chain, and increased with the increase of gas flow rate or liquid viscosity. These results provide an understanding for gas-liquid mass transfer in non-Newtonian fluids.

Application of time–frequency entropy from wake oscillation to gas–liquid flow pattern identification

Gas–liquid two-phase flow abounds in industrial processes and facilities. Identification of its flow pattern plays an essential role in the field of multiphase flow measurement. A bluff body was introduced in this study to recognize gas–liquid flow patterns by inducing fluid oscillation that enlarged differences between each flow pattern. Experiments with air–water mixtures were carried out in horizontal pipelines at ambient temperature and atmospheric pressure. Differential pressure signals from the bluff-body wake were obtained in bubble, bubble/plug transitional, plug, slug, and annular flows. Utilizing the adaptive ensemble empirical mode decomposition method and the Hilbert transform, the time–frequency entropy S of the differential pressure signals was obtained. By combining S and other flow parameters, such as the volumetric void fraction β, the dryness x, the ratio of density φ and the modified fluid coefficient ψ, a new flow pattern map was constructed which adopted S（1–x）φ and （1–β）ψ as the vertical and horizontal coordinates, respectively. The overall rate of classification of the map was verified to be 92.9% by the experimental data. It provides an effective and simple solution to the gas–liquid flow pattern identification problems.

Study on Technology for Quenching Catalytic Pyrolysis Gas

This article describes the application of technology for quenching catalytic pyrolysis gas at the Daqing commercial CPP test unit and the Shenyang commercial CPP production unit.On the basis of results for application of the Shenyang CPP unit this paper puts forward an improved process flow scheme for quenching the pyrolysis gas and made calculations using the process flowsheet software.Case Ⅰ of the process flow scheme,which is designed for full circulation of slurry,intends to use the pyrolysis light oil and fresh feed oil as the quenching media with the product slurry oil and fresh feedstock being discharged from the quench cooler bottom and routed directly to the reactor so that the fresh feed oil can be preheated prior to pyrolysis.Case Ⅱ of the process flow scheme intends to adopt recycle oil as the quenching medium with the product slurry and recycle oil being discharged from the quench cooler bottom to the fractionator,which then delivers the slurry from the bottom.These two cases for improving the process flow diagram can all effectively control the density and viscosity of the quenching medium to secure the smooth operation of quench cooler.

Experimental Study on the Flow Around Two Tandem Cylinders with Unequal Diameters

In this paper, flow around two circular cylinders in tandem arrangement with unequal diameters has been investigated using the particle image velocimetry technique(PIV) in a water channel. The upstream to downstream diameter ratio was kept constant at d/D = 2/3, the centre-to-centre distance was varied from 1.2D to 5D and the Reynolds number was varied from 1200 to 4800. The flow characteristics were analyzed through ensemble-averaged patterns of velocity, vorticity, normalized Reynolds stress contours and streamlines. Based on ensemble-averaged and instantaneous flow fields, different flow patterns, including single-wakeshedding at small spacing ratio, bi-stable flow behavior(alternating behavior of reattachment and vortex shedding) at intermediate spacing ratio and co-shedding pattern at large spacing ratio were observed. The effects of Reynolds number and the centre-to-centre spacing ratio on flow patterns and turbulent characteristics were also investigated. It was found that the diameter ratio appears to have a certain effect on the flow patterns at intermediate spacing ratios, where the reattachment of shear layer depends on the lateral width of the wake flow in the lee of the upstream cylinder. Extensive discussion on the distributions of Reynolds stress and turbulent kinetic energy was presented.

Computation and measurement for distributions of temperature and soot volume fraction in diffusion flames

A combined computational and experimental investigation to examine temperature and soot volume fraction in coflow ethylene-air diffusion flames was presented.A numerical simulation was conducted by using a relatively detailed gas-phase chemistry and complex thermal and transport properties coupled with a semi-empirical two-equation soot model.Thermal radiation was calculated using the discrete ordinates method.An image processing technique and a decoupled reconstruction method were used to simultaneously measure the distributions of temperature and soot volume fraction.The results show that the maximum error for temperature does not exceed 10% between the prediction and the measurement.And the maximum error is 6.9% for soot volume fraction between prediction and measurement.Additional simulations were performed to explore the effects of global equivalence ratio on diffusion flames and the soot formation.The results display that the soot formation increases with decreasing the coflow air velocity.And the soot formation in each case appears in the annular region,where the temperature ranges from about 1 000 K to 2 000 K and the profile becomes taller and wider when the coflow air is decreased.

Experimental Study of Airflow-Mixture in HVAC Unit by Using PIV

In this paper, experimental results are reported about, especially, effect of turbulence in airflow-mixture in HVAC （heating, ventilating, air-conditioning） unit. A flow channel in this study has same characters as actual HVAC unit, such as bent rectangular duct, a heater unit and a flow control door. The experiment was carried out to obtain verification data for analysis by using PIV （particle image velocimetry） system. Moreover, temperature map in the channel was also obtained by using thermocouples. Reynolds number is set to 12800. As a result of this study, representative velocity distributions and Reynolds stress distributions were obtained. It was found that stress value is quite high （maximum 1.4） by preliminary turbulence and mixture in the duct. In addition, it was also found that temperature diffusion is promoted by mixing around door.

Determination of Strouhal Numbers at High Reynolds Numbers

Leeward of natural elevations, like mountains and hills, the air flow becomes turbulent and often times damaging and hazardous to aviation and downwind populations. There is currently a trend for massive construction projects, the result of which are megastructures that behave similarly to these natural elevations and create analogous turbulence conditions. Examples five mega projects were analyzed, and it was estimated that the Reynolds number variation in these buildings, is from 6.10g and 7.109, for winds between 10 m/s and 50 m/s. In this work, the authors present a first numerical approach to this phenomenon by calculating the Strouhal numbers induced by winds blowing against large-volume bodies, in the range of high Reynolds numbers. For this study, satellite images depicting von K^irm^n cloud streets leeward of isolated islands were used. The methodology employed was based on a satellite image where streets watch von K^rnfin vortex, from NOAA-ARL （National Oceanic and Atmospheric Administration-Air Resource Laboratory） prognosis was obtained for a grid point near the island, then determined the inversion layer and meteorological data （wind, temperature and pressure）, was measured from the satellite image the distances separating the vortices to calculate the period, the Reynolds number and Strouhal. The studied results of the cases are displayed graphically, where it is possible to observe a data dispersion as well as a rising trend of the Strouhal number as the Reynolds number increases.

Flow characteristics by particle image velocimetry in liquefied natural gas vaporizer model with several baffles

Shell-and-tube vaporizers are the most commonly used and dominated types of vaporizers in liquefied natural gas （LNG） realm. Due to efficient performance, shell-side flow in this type of vaporizers has received considerable attention and has been investigated extensively. However, the detailed flow structure in the shell needs to be determined for reliable and effective design. Therefore, the objective of this study was to clarify the flow structure in shell by particle image velocimetry （PIV）. Experiments were conducted using two types of model; 15% baffle cut having inlet and outlet positions !n the direction of 90° to the cut and 30% baffle cut having inlet and outlet positions in the direction of 180° to the cut. Each test section is 169 mm in inner diameter and 344.6 mm in length. The flow features were characterized in different baffle cuts with regards to the velocity vector field and velocity distribution. The results show that the flow characteristics of 15% baffle cut type vaporizer are comparable to those of 30% baffle cut type vaporizer.

Study on Causes of a Local Heavy Rainstorm Process in Shandong Province

Based on conventional meteorological observation data, NECP 1°×1° reanalysis data, precipitation data from automatic weather stations on the ground, FY- 2E satellite cloud images, and so forth, the circulation background, formation mechanism and features of a satellite cloud image of a local heavy rainstorm process in Shandong Province during August 8-9 in 2010 were analyzed. The results showed that the slow eastward movement of short-wave trough at middle and high latitudes, the stable maintenance of the subtropical high and ground cyclone, and the strong development of extra low-level southeast flow were large-scale circulation back- grounds of occurrence of the rainstorm; the rainstorm generated under the effects of mesoscale echo clusters or echo belts and mesoscale convective cloud clusters; precipitation mainly happened in periods when convective cloud clusters generated, developed and matured, and short-time heavy precipitation mainly appeared in the west, southwest and south of convective cloud clusters; extra low-level southeast flow was very conducive to the occurrence of short-time heavy precipitation; mesoscale convective systems rose in the whole troposphere, and the constant enhancement of low-level θse frontal zone provided favorable unstable energy for the occurrence of convective heavy rainfall.

Prediction of Fluid Velocity Distribution near a Rising Bubble

Flow and concentration fields of liquid phase in a gas-liquid contacting system are simulated to showthe Rayleigh convection by utilizing the finite-element method. The Schlieren images in CO2-ethanol system provided direct visual verification of the present simulation, and the simulated results were well consistent with theexperimental observation. The influence of the Rayleigh convection on mass transfer is analyzed qualitatively andquantitatively based on the simulated and the experimental results.

Delaying Modified QUICK Scheme and its Application in Slug Flow

The National Laboratory of Multiphase Flow in Power Engineering Xi' an Jiaotong University, Xi' an 710049, China Abstract:Calculations of several classic questions in numerical heat transfer with delaying modified QUICK scheme show good agreement with benchrnark. Combining volume of fluid model with the well known SIMPLEC method. the reasonanble Tgylor bubble shape has ben obtained by using delaying modified QUICK scheme and donor acceptor scheme of interfacial advection respectively. At the same the the stream field and the liquid film thickness around the Taylor bubble have been well figured out

The Two-Dimensional Supersonic Flow and Mixing with a Perpendicular Injection in a Scramjet Combustor

A numerical investigation has been performed on supersonic mixing of hydrogen with air in a Scramjet (Supersonic Combustion Ramjet) combustor and its flame holding capability by solving Two-Dimensional full Navier-Stokes equations. The main flow is air entering through a finite width of inlet and gaseous hydrogen is injected perpendicularly from the side wall. An explicit Harten-Yee Non-MUSCL Modified-flux-type TVD scheme has been used to solve the system of equations, and a zero-equation algebraic turbulence model to calculate the eddy viscosity coefficient. In this study the enhancement of mixing and good flame holding capability of a supersonic combustor have been investigated by varying the distance of injector position from left boundary keeping constant the backward-facing step height and other calculation parameters. The results show that the configuration for small distance of injector position has high mixing efficiency but the upstream recirculation can not evolved properly which is an important factor for flame holding capability. On the other hand, the configuration for very long distance has lower mixing efficiency due to lower gradient of hydrogen mass concentration on the top of injector caused by the expansion of side jet in both upstream and downstream of injector. For moderate distance of injector position, large and elongated upstream recirculation can evolve which might be activated as a good flame holder.