Hydrogen hollow cathode ion source

A source of hydrogen ions is disclosed and includes a chamber having at one end a cathode which provides electrons and through which hydrogen gas flows into the chamber. Screen and accelerator grids are provided at the other end of the chamber. A baffle plate is disposed between the cathode and the grids and a cylindrical baffle is disposed coaxially with the cathode at the one end of the chamber. The cylindrical baffle is of greater diameter than the baffle plate to provide discharge impedance and also to protect the cathode from ion flux. An anode electrode draws the electrons away from the cathode. The hollow cathode includes a tubular insert of tungsten impregnated with a low work function material to provide ample electrons. A heater is provided around the hollow cathode to initiate electron emission from the low work function material

System for the measurement of ultra-low stray light levels

An apparatus is described for measuring the effectiveness of stray light suppression light shields and baffle arrangements used in optical space experiments and large space telescopes. The light shield and baffle arrangement and a telescope model are contained in a vacuum chamber. A source of short, high-powered light energy illuminates portions of the light shield and baffle arrangement and reflects a portion of same to a photomultiplier tube by virtue of multipath scattering. The resulting signal is transferred to time-channel electronics timed by the firing of the high energy light source allowing time discrimination of the signal thereby enabling the light scattered and suppressed by the model to be distinguished from the walls and holders around the apparatus

Further analysis of the effects of baffles on combustion instability

A computerized analytical model, developed to predict the effects of baffles on combustion instability, was modified in an effort to improve the ability to properly predict stability effects. The model was modified: (1) to replace a single spatially-averaged response factor by separate values for each baffle compartment; (2) to calculate the axial component of the acoustic energy flux, and (3) to permit analysis of traveling waves in a thin annular chamber. Allowance for separate average response factors in each baffle compartment was found to significantly affect the predicted results. With this modification, an optimum baffle length was predicted which gave maximum stability

Solar cell angular position transducer

An angular position transducer utilizing photocells and a light source is disclosed. The device uses a fully rotatable baffle which is connected via an actuator shaft to the body whose rotational displacement is to be measured. The baffle blocks the light path between the light source and the photocells so that a constant semicircular beam of light reaches the photocells. The current produced by the photocells is fed through a resistor, a differential amplifier measures the voltage drop across the resistor which indicates the angular position of the actuator shaft and hence of the object

Floating baffle to improve efficiency of liquid transfer from tanks

When liquid tank is full, baffle is held up against a stop on top of shaft to prevent restriction of flow from outlet. As tank is being emptied, baffle, floating on top of liquid surface, descends with liquid level toward outlet until it reaches its bottom stop. Baffle prevents gas pull-through until practically all liquid is emptied from tank

Theoretical evaluation of rigid baffles in the suppression of combustion instability

An analytical technique for the prediction of the effects of rigid baffles on the stability of liquid propellant combustors is presented. This analysis employs both two and three dimensional combustor models characterized by concentrated combustion sources at the chamber injector and a constant Mach number nozzle. An eigenfunction-matching method is used to solve the linearized partial differential equations describing the unsteady flow field for both models. Boundary layer corrections to this unsteady flow are in a mechanical energy dissipation model to evaluate viscous and turbulence effects within the flow. An integral instability relationship is then employed to predict the decay rate of the oscillations. Results of this analysis agree qualitatively with experimental observations and show that sufficient dissipation exists to indicate that the proper mechanism of baffle damping is a fluid dynamic loss. The response of the dissipation model to varying baffle blade length, mean flow Mach number, oscillation amplitude, baffle configuration, and oscillation mode is examined

Ring baffle pressure distribution and slosh damping in large cylindrical tanks

An investigation was conducted to determine the pressure loads and damping associated with rigid ring baffles in relatively large cylindrical tanks. The radial and circumferential pressure distribution, as well as the damping, was measured on a ring baffle subjected to fundamental antisymmetric slosh in a 284-cm-diameter rigid tank. Experimental and analytical data are presented as a function of slosh velocity or amplitude, baffle spacing, and baffle locations both above and below the liquid surface. Results suggest that pressure distributions and damping values can be determined from available theories for the design of single and multiple baffle configurations

Hydraulic Modelling and Optimization of a Wastewater Treatment System for Developing Nations Using Computational Fluid Dynamics

Waste stabilization pond (WSP) is globally one of the most popular wastewater treatment options because of its high efficiency and low cost. However, no rigorous assessment of WSPs that account for cost in addition to hydrodynamics and treatment efficiency has been performed. A study was conducted that utilized Computational Fluid Dynamics (CFD) coupled with an optimization program to optimize the selection of the best WSP configuration based on cost and treatment efficiency. Several designs generated by the CFD/optimization model showed that both shorter and longer baffles, alternative depths, and reactor length to width ratios could improve the hydraulic efficiency of the ponds at a reduced overall construction cost. In addition, a study was conducted on the optimized WSP which consisted of an anaerobic, facultative, and a maturation stage whose baffle orientation, length to width ratio, was specified by a CFD model prediction and was compared with a three stage WSP designed according to literature suggested reactor geometric configurations. Experimental tests were performed on a pilot scale version of the threestage WSP where the removal performance was based on a number of parameters (Faecal coliform, pH, TDS, and Conductivity). Results showed that the significantly lower cost design based on the optimized CFD simulations displayed slightly better removal performance compared to the standard WSP design developed from literature data. The results of this study clearly showed that unit treatment process designs based on rigorous numerical optimization can aid in producing cost effective designs that make it more possible for developing nations to incorporate adequate and effective sanitation

The Baffle V and Erect Influence on the Distilation Sieve Plate Toward Mixing System Air-water

The baffle influence to the degree of liquid mixing in the plate and the pressure drop on the plate has beenstudied in this research. The operational pressure in this research is limited in the atmospheric pressure .Thedistillation column that used in the research has 0.2m diameter and 1.4 m height with the distance betweentrays is 0.4 m. The research was carried out by to flows water into the column with the flow rate of water are105 l/h, 149 l/h, 189 l/h and to flows air into the lower of the column with superficial speed from 0 to 0.3 m/s.After steady state is required the dry plate pressure and the pressure drop because the difference between theheight of clear liquid and the height of foam is measured. The mixing degree is determined by stimulusresponse method, i.e flows air into the system, then give a tracer (i.e. NaCl saturated 20 CC) as a stimulatorthat injected into the fuild to the basin. This experiment will give the data off the concentrations and the time.The conclusion of this research is the pressure drop by dry plate can provide the correlation hD = 8.34926( )( ) Lh GgUρρ22. The value of residual pressure drop at the column of sieve plate without baffle and with use abaffle in this study almost constant, i.e. 1-2 mm H2O. The relation among the Peclet number, the F factor andthe flow rate of water can expresse in empirical equation are : for without baffle Pe = 0.3837 F0.9254 Q-0.05229;Baffle V, Pe = 0.00005306 F-2.341 Q-1.005; vertical Baffle Pe = 0.004989 F-1.775 Q-0.4848. The presentation of thedifference of the clear liquid's height in the condition without use a baffle are 86,88% for the V baffle,53,55% for the vertical baffle (105 l/h); 73,5% for V baffle, 50,64% for the vertical baffle (149 l/h); 84,34 forV baffle, 65,58% for vertical baffle (189 l/h). The value of EMV / EOG for the experiment without use a baffle isgreater than the value of EMV / EOG fot the experiment use a baffle