Calculation of Resonant Radiation Power of a Direct Sodium Lamp With Low Pressure

2018 ◽  
Vol 7 (3.19) ◽  
pp. 92
Author(s):  
Sveshnikov V.K ◽  
Bazarkin A.F ◽  
Kurenschikov A.V
Keyword(s):  
Cross Section ◽  
Discharge Tube ◽  
Radiation Power ◽  
Low Pressure ◽  
Resonance Radiation ◽  
Cylindrical Shape ◽  
Tube Cross Section ◽  
Calculation Technique ◽  
Sodium Lamp ◽  
Resonant Radiation

They consider the calculation technique for the resonance radiation power of a direct low-pressure sodium lamp with a sickle-shaped discharge tube cross-section. The calculation of the sodium discharge radiation power is difficult in such a tube, as compared with the calculation in a cylindrical shape tube. The dependence of the relative output of sodium discharge resonant radiation occurring in equivalent discharge tubes in the form of a parallelepiped and a cylinder is based on the involvement of the theory by M. Cayless. The obtained results were used to determine the power of DNaO-85M lamp resonant radiation. They presented the scheme of the device to study the influence of the tube geometry on sodium discharge power. It is shown that the power of the resonance radiation generated by an equivalent discharge will be the greater, the larger the cross section of the discharge tube. The discrepancy between the calculated and the experimental data for resonant radiation power determination in a crescent-shaped tube is less than 4%.  

Starting System for Darrieus Water Turbine of Tidal Stream Electricity Generation

2016 ◽  
Author(s):  
Seiji Shimizu ◽  
Masayuki Fujii ◽  
Tetsuya Sumida ◽  
Kenji Sasa ◽  
Yasuhiro Kimura ◽  
...  
Keyword(s):  
Experimental Data ◽  
Cross Section ◽  
Electricity Generation ◽  
Lift Coefficient ◽  
Vertical Axis ◽  
Cylindrical Shape ◽  
Water Turbine ◽  
Tidal Stream ◽  
Tidal Stream Turbine ◽  
Original Experimental Data

Darrieus type vertical axis water turbine in a cylindrical shape which consists of some straight blades is simple, efficient and easy to install a generator upward. However, it has difficulty in starting revolution. As a method to cope with such a problem, a starting revolution assist mechanism was fabricated and set on a prototype of the turbine. Assist experiment was carried out. It resulted helping well the starting revolution. The improved prototype of tidal stream turbine can generate 1.4 W under a water flow of 1 m/s where impossible to self-start. Besides that, Darrieus water turbine’s generating torque property was investigated by the famous original experimental data of lift coefficient Cl and drag coefficient Cd for straight blades of NACA63 3-018 cross section. It was found that setting two or four blades in a turbine would help to improve the difficulty of starting revolution.

scholarly journals Spatial Non-uniformity in Discharges in Low Pressure Helium and Neon

1987 ◽  
Vol 40 (3) ◽  
pp. 383 ◽  
Author(s):  
J Fletcher ◽  
PH Purdie
Keyword(s):  
Monte Carlo Simulation ◽  
Cross Section ◽  
Cross Sections ◽  
Ground State ◽  
Low Pressure ◽  
Photon Flux ◽  
Cross Section Data ◽  
Section Data ◽  
Neon Gas ◽  
Wavelength Distribution

Low current, low pressure, steady state Townsend discharges in helium and neon gas have been investigated using the photon flux technique. Such discharges have been found to exhibit spatial non-uniformity resulting in luminous layers throughout the discharge. The separation and structure of these layers has been investigated experimentally in both gases along with the wavelength distribution of the photon flux. A Monte Carlo simulation of the discharge in neon has been used to gain information on the cross sections necessary to describe these discharges. It is found that direct excitaton of ground state atoms to the resonance level of each gas is less than indicated by some published cross section data.

The Pressure Field at the Output From a Low Pressure Exhaust Hood and Condenser Neck of the 1090 MW Steam Turbine: Experimental and Numerical Research

2018 ◽  
Author(s):  
Michal Hoznedl ◽  
Antonín Živný ◽  
Aleš Macálka ◽  
Robert Kalista ◽  
Kamil Sedlák ◽  
...  
Keyword(s):  
Boundary Condition ◽  
Steam Turbine ◽  
Cross Section ◽  
Static Pressure ◽  
Cooling Water ◽  
Low Pressure ◽  
Maximum Temperature ◽  
Angle Distribution ◽  
Exhaust Hood ◽  
Last Stage

The paper presents the results of measurements of flow parameters behind the last stage of a 1090 MW nominal power steam turbine in a nuclear power plant. The results were obtained by traversing a pneumatic probe at a distance of about 100 mm from the trailing edges of the LSB (Last Stage Blade). Furthermore, both side walls as well as the front wall of one flow of the LP (Low Pressure) exhaust hood were fitted with a dense net of static pressure taps at the level of the flange of the turbine. A total of 26 static pressures were measured on the wall at the output from the LP exhaust hood. Another 14 pressures were measured at the output from the condenser neck. The distribution of static pressures in both cross sections for full power and 600 and 800 MW power is shown. Another experiment was measured pressure and angle distribution using a ball pneumatic probe in the condenser neck area in a total of four holes at a distance up to 5 metres from the neck wall. The turbine condenser is two-flow design. In one direction perpendicular to the axis of the turbine cold cooling water comes, it heats partially. It then reverses and it heats to the maximum temperature again. The different temperature of cooling water in the different parts of the output cross section should influence the distribution of the output static pressure. Differences in pressures may cause problems with uneven load of the tube bundles of the condenser as well as problems with defining the influential edge output condition in CFD simulations of the flow of the cold end of the steam turbine Due to these reasons an extensive 3D CFD computation, which includes one stator blade as well as all moving blades of the last stage, a complete diffuser, the exhaust hood and the condenser neck, has been carried out. Geometry includes all reinforcing elements, pipes and heaters which could influence the flow behaviour in the exhaust hood and its pressure loss. Inlet boundary conditions were assumed for the case of both computations from the measurement of the flow field behind the penultimate stage. The outlet boundary condition was defined in the first case by an uneven value of the static pressure determined by the change of the temperature of cooling water. In the second case the boundary condition in accordance with the measurement was defined by a constant value of the static pressure along all the cross section of the output from the condenser neck. Results of both CFD computations are compared with experimental measurement by the distribution of pressures and other parameters behind the last stage.

CW HCN laser gain in a hollow dielectric rectangular cross-section discharge tube

1979 ◽  
Vol 19 (3) ◽  
pp. 359-361 ◽  
Author(s):  
J. L. Bruneau ◽  
P. Belland ◽  
T. Lebertre ◽  
D. Veron
Keyword(s):  
Cross Section ◽  
Discharge Tube ◽  
Rectangular Cross Section ◽  
Laser Gain ◽  
Hcn Laser

Coupled-Physics Modeling of a Lithium-Ion Battery Cylindrical Cell Microstructure

2012 ◽  
Author(s):  
Peter N. Doval ◽  
Ilya V. Avdeev
Keyword(s):  
Cross Section ◽  
Automotive Industry ◽  
Hybrid Electric Vehicle ◽  
Emerging Market ◽  
Lithium Ion ◽  
Functional Materials ◽  
Battery Pack ◽  
Cylindrical Shape ◽  
Fe Model ◽  
Battery Cell

Safety of consumer vehicles is an extremely important consideration for the automotive industry. An emerging market in the automotive industry today is the electric and hybrid-electric vehicle market. As environmental concerns grow, such vehicles will become a necessity for manufacturers to remain within increasingly stringent emissions regulations. A recent problem with the high-voltage lithium-ion batteries used in many of these vehicles is that of thermal runaway following a severe collision. This paper represents our early attempt to look at one aspect of this extensive project — a coupled-physics model of battery cell microstructure. In this case, couple-physics refers only to thermal-structural coupling and the microstructure being studied here is the laminate-level structure. A 2-D finite element model of a lithium-ion cell was therefore developed. This 2-D model of the cell, also called a jellyroll, is a cross-section cut of one cell within a battery pack. Each battery cell is an assembly of alternating thin sheets of functional materials (anode, separator and cathode), which are rolled into a cylindrical shape. The cross-section then takes the form of a layered spiral. The typical cell is made of an aluminum cathode with coating, copper anode with coating, and a non-linear, viscoelastic polymer separator. Once the 2-D jellyroll FE model was created, some initial structural element simulations were run to validate the geometry setup and model integrity. Next, thermal-structural coupled-field simulations were run to investigate stress propagation resulting from thermal loads as well as the same loading cases performed with the structural-only model. Different loading conditions, including uniaxial stress-strain state, hydrostatic pressure test, and thermo-mechanical loading were simulated. The results from the simulations performed in the project set the groundwork of future models involving electrical properties and models of 3-D cells and the full battery pack.

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