Results of the Study Rotor Wheels Supersonic Microturbines with a Large Angle of Rotation of the Flow

2015 ◽  
Vol 752-753 ◽  
pp. 884-889 ◽  
Author(s):  
Andrey Yu. Fershalov ◽  
Mikhail Yu. Fershalov ◽  
Yuriy Ya. Fershalov ◽  
Timofey V. Sazonov
Keyword(s):  
Mach Number ◽  
Gas Flow ◽  
Large Angle ◽  
Experimental Investigations ◽  
Flow Rates ◽  
Ratio Speed ◽  
Supersonic Gas Flow ◽  
Angle Of Rotation

The article presents the results of experimental investigations of rotor wheels supersonic microturbines with a large angle of rotation of the flow. The characteristics of the studied rotor wheels. The analysis of the results of the study ratio speed of rotor wheels, depending on the Mach number. Recommendations for the design working wheels microturbines operating at high supersonic gas flow rates.

scholarly journals Self-Consistent Cathode–Plasma Coupling and Role of the Fluid Flow Approach in Torch Modeling

2021 ◽  
Author(s):  
Margarita Baeva ◽  
Tao Zhu ◽  
Thorben Kewitz ◽  
Holger Testrich ◽  
Rüdiger Foest
Keyword(s):  
Mach Number ◽  
Gas Flow ◽  
Stokes Equations ◽  
Cathode Plasma ◽  
Plasma Parameters ◽  
Plasma Properties ◽  
Flow Rates ◽  
High Mach Number ◽  
Self Consistent ◽  
High Mach

AbstractA two-dimensional and stationary magnetohydrodynamic model of a plasma spray torch operated with argon is developed to predict the plasma properties in a steady operating mode. The model couples a submodel of a refractory cathode and its non-equilibrium boundary layer to a submodel of the plasma in local thermodynamic equilibrium in a self-consistent manner. The Navier–Stokes equations for a laminar and compressible flow are solved in terms of low and high Mach number numerical approaches. The results show that the Mach number can reach values close to one. Simulations are performed for electric currents of 600 A and 800 A, and gas flow rates of 40, 60, and 80 NLPM. The plasma parameters obtained by the two approaches differ, and the differences become more pronounced for higher currents and gas flow rates. The arc voltage, the electric power, and the thermal efficiency from both the low and high Mach number models of the plasma agree well with experimental findings for a current of 600 A and a flow rate of 40 NLPM. For higher currents and gas flow rates, the results of the low and high Mach number models gradually differ and underline the greater appropriateness of the high Mach number model.

Biodegradation of Styrene Vapor in a Biofilter

2013 ◽  
Vol 275-277 ◽  
pp. 2329-2332 ◽  
Author(s):  
Xian Sheng Huang ◽  
Hao Wu
Keyword(s):  
Gas Flow ◽  
Experimental Investigations ◽  
Flow Rates ◽  
Operational Conditions ◽  
New Class ◽  
Filter Materials ◽  
Air Stream ◽  
Volatile Organic ◽  
Maximum Elimination Capacity ◽  
Styrene Removal

Volatile organic compounds (VOCs) are a new class of air pollutants posing threat to the environment. Newer technologies are being developed for their control among which biofiltration seem to be most attractive. Biofiltration of styrene vapor from air stream was discussed in this study. Experimental investigations were conducted on a laboratory scale biofilter, containing mixture of compost and polystyrene inert particles as the filter materials. Mixed consortium of activated sludge was used as an inoculum. The continuous performance of biofilter for styrene removal was monitored for different concentrations and flow rates. The removal efficiencies decreased at higher concentrations and higher gas flow rates. A maximum elimination capacity of 85g/(m3•h) was achieved. The response of biofilter to upset loading operation showed that the biofilm in the biofilters was quite stable and quickly adapted to adverse operational conditions.

Experimental Investigations of Laminar, Transitional to Turbulent Gas Flow in a Micro-Channel

2010 ◽  
Author(s):  
Chungpyo Hong ◽  
Toru Yamada ◽  
Yutaka Asako ◽  
Mohammad Faghri ◽  
Koichi Suzuki ◽  
...  
Keyword(s):  
Mach Number ◽  
Flow Regime ◽  
Gas Flow ◽  
Flow Characteristics ◽  
Channel Length ◽  
Transitional Flow ◽  
Experimental Investigations ◽  
Compressibility Effect ◽  
Micro Channels ◽  
Wide Range

This paper presents experimental results on flow characteristics of laminar, transitional to turbulent gas flows through micro-channels. The experiments were performed for three micro-channels. The micro-channels were etched into silicon wafers, capped with glass, and their hydraulic diameter are 69.48, 99.36 and 147.76 μm. The pressure was measured at seven locations along the channel length to determine local values of Mach number and friction factor for a wide range of flow regime from laminar to turbulent flow. Flow characteristics in transitional flow regime to turbulence were obtained. The result shows that f·Re is a function of Mach number and higher than incompressible value due to the compressibility effect. The values of f·Re were compared with f·Re correlations in available literature.

Biodegradation of DCM Vapor in a Biofilter

2013 ◽  
Vol 395-396 ◽  
pp. 561-564
Author(s):  
Hong Tao Sun ◽  
Liang Li ◽  
Xin Gang Hao
Keyword(s):  
Gas Flow ◽  
Experimental Investigations ◽  
Continuous Performance ◽  
Flow Rates ◽  
Operational Conditions ◽  
Filter Materials ◽  
Air Stream ◽  
Inert Particles ◽  
Maximum Elimination Capacity ◽  
Removal Efficiencies

Biofiltration of DCM vapor from air stream was discussed in this study. Experimental investigations were conducted on a laboratory scale biofilter, containing mixture of compost and polystyrene inert particles as the filter materials. Activated sludge was used as an inoculum. The continuous performance of biofilter for DCM removal was monitored for different concentrations and flow rates. The removal efficiencies decreased at higher concentrations and higher gas flow rates. A maximum elimination capacity of 8g/(m3·h) was achieved. The response of biofilter to upset loading operation showed that the biofilm in the biofilters was quite stable and quickly adapted to adverse operational conditions.

Biodegradation of 1,2-Dichloroethane Vapor in a Biofilter

2013 ◽  
Vol 807-809 ◽  
pp. 249-252
Author(s):  
Liang Li ◽  
Yan Wu ◽  
Xin Gang Hao
Keyword(s):  
Activated Sludge ◽  
Gas Flow ◽  
Experimental Investigations ◽  
Continuous Performance ◽  
Flow Rates ◽  
Operational Conditions ◽  
Filter Materials ◽  
Air Stream ◽  
Inert Particles ◽  
Removal Efficiencies

Biofiltration of 1,2-dichloroethane vapor from air stream was discussed in this study. Experimental investigations were conducted on a laboratory scale biofilter, containing mixture of compost and polystyrene inert particles as the filter materials. Mixed consortium of activated sludge was used as an inoculum. The continuous performance of biofilter for 1,2-dichloroethane removal was monitored for different concentrations and flow rates. The removal efficiencies decreased at higher concentrations and higher gas flow rates. The response of biofilter to upset loading operation showed that the biofilm in the biofilters was quite stable and quickly adapted to adverse operational conditions.

Experimental Investigations of Turbulent Gas Flow in a Micro-Channel

2011 ◽  
Author(s):  
Shinichi Matsushita ◽  
Chungpyo Hong ◽  
Yutaka Asako ◽  
Ichiro Ueno
Keyword(s):  
Mach Number ◽  
Turbulent Flow ◽  
Friction Factor ◽  
Gas Flow ◽  
Experimental Investigations ◽  
Micro Channel ◽  
Pressure Transducers ◽  
Friction Factors ◽  
Turbulent Flow Regime ◽  
Turbulent Gas Flow

This paper presents experimental investigations on turbulent gas flow characteristics of nitrogen gas through a micro-channel. The micro-channels were etched into silicon wafers, capped with glass, and their hydraulic diameter is 147.76 micro meters. The micro-channel was designed with a main flow channel and seven side channels, which lead to the pressure transducers. The stagnation pressure was designated in such a way that the flow is in turbulent flow regime. The outlet of the channel faced to the atmosphere. The pressures of the main channel at seven locations were measured by gauge pressure transducers to determine local values of Mach number. And the pressure differences of each pressure ports were measured by differential pressure transducers to obtain the pressure losses precisely. The pressure distribution of turbulent gas flow through a micro-channel falls steeply and Mach number increases near the outlet with increasing the inlet pressure due to flow acceleration. Both Darcy friction factor and Fanning friction factor were obtained for turbulent flow. The result shows that the obtained both friction factors were evaluated as a function of Reynolds number on the Moody chart. The values of Darcy friction factors differ from Blasius correlation for turbulent flow regime due to the compressibility effects, however the values of Fanning friction factors coincide with Blasius correlation.

Experimental Investigations of Laminar, Transitional to Turbulent Gas Flow in Rib-Patterned Micro-Channels

2011 ◽  
Author(s):  
Chungpyo Hong ◽  
Toru Yamada ◽  
Yutaka Asako ◽  
Mohammad Faghri ◽  
Ichiro Ueno
Keyword(s):  
Mach Number ◽  
Friction Factor ◽  
Gas Flow ◽  
Flow Direction ◽  
Channel Length ◽  
Experimental Investigations ◽  
Patterned Surfaces ◽  
Micro Channels ◽  
Wide Range ◽  
Turbulent Gas Flow

The effects of rib-patterned surfaces on laminar, transitional to turbulent gas flow in micro-channels were experimentally investigated in the present study. The experiments were performed for two micro-channels having either smooth or rib-patterned surfaces. The micro-channels were etched into silicon wafers and capped with glass substrates. The micro-ribs were patterned on the microchannel surfaces and oriented perpendicular to the flow direction. The pressure was measured at seven locations along the channel length to determine local values of Mach number and friction factor for a wide range of flow regime from laminar to turbulent flow. The friction factors with the hydraulic diameter based on the rib-to-upper-wall height were compared with that for incompressible theory on Moody chart. The values of the product of friction factor and Reynolds number (f·Re) as a function of Mach number were also compared with those of smooth micro-channels and incompressible theory.

Experimental Investigation of Gaseous Flow in a Micro-Tube

2009 ◽  
Author(s):  
Yasuhiro Yoshida ◽  
Chungpyo Hong ◽  
Yutaka Asako ◽  
Koichi Suzuki
Keyword(s):  
Mach Number ◽  
Gas Flow ◽  
Electrical Discharge Machining ◽  
Tube Length ◽  
Experimental Investigations ◽  
Arbitrary Lagrangian Eulerian ◽  
Atmospheric Conditions ◽  
Compressibility Effect ◽  
Wide Range ◽  
Tube Exit

Experimental investigations on nitrogen gas flow characteristics were performed for a micro-tube. The micro-tube was fabricated in a stainless steel block by electrical discharge machining (EDM). The tube diameter was 326 μm and the ratio of length to diameter was 200. The stagnation pressure was chosen in such a way that the exit Mach number ranged from 0.1 to 1.4. The outlet pressure was fixed at atmospheric conditions. The pressure was locally measured at five locations along tube length to determine local values of Mach number and friction factor for a wide range of flow regime from laminar to turbulent flow. The result shows that f·Re is a function of Mach number and higher than incompressible value, 64 due to the compressibility effect. The values of f·Re were compared with f·Re correlation in literature. In additional experiments, Mach number at the micro-tube exit was measured by using a Shadowgraph system which visualizes the shock wave of the gas. The micro-tube with 400 μm in diameter was used for the experiment. The super sonic flow was observed since Mach number at the micro-tube exit was beyond unity. The experimental results for laminar flow were compared with the numerical results obtained by the arbitrary-Lagrangian-Eulerian method. The both results are in excellent agreement.

TO THE THEORY OF UNSTEADY SEPARATION AND INTERACTION OF BOUNDARY LAYER WITH SUPERSONIC GAS FLOW

2018 ◽  
Vol 49 (4) ◽  
pp. 415-427
Author(s):  
Igor Ivanovich Lipatov ◽  
Vladimir Yakovlevich Neiland
Keyword(s):  
Boundary Layer ◽  
Gas Flow ◽  
Unsteady Separation ◽  
Supersonic Gas Flow

scholarly journals Simulation of Gas Flow Over a Micro Cylinder

2009 ◽  
Author(s):  
Yuan Hu ◽  
Quanhua Sun ◽  
Jing Fan
Keyword(s):  
Reynolds Number ◽  
Mach Number ◽  
Drag Coefficient ◽  
Gas Flow ◽  
Rarefied Gas ◽  
Low Reynolds Number ◽  
Pressure Drag ◽  
Low Reynolds ◽  
Rarefied Gas Effect ◽  
Gas Effect

Gas flow over a micro cylinder is simulated using both a compressible Navier-Stokes solver and a hybrid continuum/particle approach. The micro cylinder flow has low Reynolds number because of the small length scale and the low speed, which also indicates that the rarefied gas effect exists in the flow. A cylinder having a diameter of 20 microns is simulated under several flow conditions where the Reynolds number ranges from 2 to 50 and the Mach number varies from 0.1 to 0.8. It is found that the low Reynolds number flow can be compressible even when the Mach number is less than 0.3, and the drag coefficient of the cylinder increases when the Reynolds number decreases. The compressible effect will increase the pressure drag coefficient although the friction coefficient remains nearly unchanged. The rarefied gas effect will reduce both the friction and pressure drag coefficients, and the vortex in the flow may be shrunk or even disappear.

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