Influence of injection angle on oil splash of herringbone gear

A large eddy simulation (LES) was performed for film cooling in the gas turbine blade involving spanwise injection angles (orientation angles). For a streamwise coolant injection angle (inclination angle) of 35°, the effects of the orientation angle were compared considering a simple angle of 0° and 30°. Two ratios of the coolant to main flow mass flux (blowing ratio) of 0.5 and 1.0 were considered and the experimental conditions of Jung and Lee (2000) were adopted for the geometry and flow conditions. Moreover, a Reynolds averaged Navier–Stokes simulation (RANS) was performed to understand the characteristics of the turbulence models compared to those in the LES and experiments. In the RANS, three turbulence models were compared, namely, the realizable k-ε, k-ω shear stress transport, and Reynolds stress models. The temperature field and flow fields predicted through the RANS were similar to those obtained through the experiment and LES. Nevertheless, at a simple angle, the point at which the counter-rotating vortex pair (CRVP) collided on the wall and rose was different from that in the experiment and LES. Under the compound angle, the point at which the CRVP changed to a single vortex was different from that in the LES. The adiabatic film cooling effectiveness could not be accurately determined through the RANS but was well reflected by the LES, even under the compound angle. The reattachment of the injectant at a blowing ratio of 1.0 was better predicted by the RANS at the compound angle than at the simple angle. The temperature fluctuation was predicted to decrease slightly when the injectant was supplied at a compound angle.

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Numerical Simulation and Experimental Study on Water Mist Fire Suppression for Cooking Fog Discharge Pipe

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.915-916.356 ◽

2014 ◽

Vol 915-916 ◽

pp. 356-361

Author(s):

Zheng Wen Xie

Keyword(s):

Design Method ◽

Fire Suppression ◽

Orthogonal Design ◽

Water Mist ◽

Simulation Software ◽

Droplet Radius ◽

Test Analysis ◽

Injection Angle ◽

Fire Extinguishing ◽

Flow Quantity

FDS simulation software was used to establish the full size lampblack physics model of single wind pipe, using the orthogonal design method design of analog calculation conditions, research in the nozzle pressure, the droplet radius, nozzle, flow quantity and injection angle parameters under different conditions of water mist fire extinguishing effect. Based on a full-scale combustion and water mist fire extinguishing experiment, the water mist fire suppression was observed and test analysis etc, to better understand the flue water mist fire extinguishing feasibility, provides the theory basis for the design of efficient, reliable flue fire extinguishing system.

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Fuel Spray Trajectory in Diesel Engines

Journal of Engineering for Power ◽

10.1115/1.3446353 ◽

1978 ◽

Vol 100 (2) ◽

pp. 326-332 ◽

Cited By ~ 3

Author(s):

M. M. Elkotb ◽

N. M. Rafat

Keyword(s):

Heat Transfer ◽

Theoretical Model ◽

Working Conditions ◽

Fuel Spray ◽

Air Velocity ◽

Spray Penetration ◽

Injection Angle ◽

Velocity Pattern ◽

Spray Volume ◽

Spray Velocity

A detailed investigation of the effect of the shape of an open combustion chamber for diesel engine on the air velocity pattern, and consequently, on the trajectory of the fuel spray is given in this paper. A theoretical model for the calculation of the spray penetration, taking into consideration the heat transfer to the droplet, the variation of the drag force with Reynolds number, and air velocity pattern, is suggested. The effect of some working conditions on the spray shape, trajectory, and penetration is experimentally studied to verify the theoretical model and to correlate the results of using different medium pressures, initial spray velocity, and injection angle on the magnitude of fuel spray diameter and spray volume.

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Diesel Knock Visualization and Frequency Analysis of Premixed Charge Compression Ignition Combustion with a Narrow Injection Angle

10.4271/2013-01-0906 ◽

2013 ◽

Cited By ~ 5

Author(s):

Stephen Sungsan Park ◽

Yongjin Jung ◽

Choongsik Bae

Keyword(s):

Frequency Analysis ◽

Compression Ignition ◽

Injection Angle ◽

Compression Ignition Combustion

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The Effect of Air Injector on the Performance of Airlift

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.516-517.1022 ◽

2012 ◽

Vol 516-517 ◽

pp. 1022-1027 ◽

Cited By ~ 5

Author(s):

Dong Hu ◽

Chuan Lin Tang ◽

Feng Hua Zhang

Keyword(s):

Flow Rate ◽

Marked Effect ◽

Pipe Wall ◽

Tangential Direction ◽

Air Injection ◽

Air Flow Rate ◽

Injection Angle ◽

Injection Methods ◽

The One ◽

Air Lift

In order to investigate the air injection method on the performance of an airlift. For this purpose an air lift system with a riser 2000 mm long and 80 mm in diameter, was designed and tested. Seven different air injection methods were used at a constant submergence. The experimental results showed a marked effect on the airlift performance when operated with different air injection methods. The arrangement of five nozzles gives the best performance, and the one nozzle is the worst. Although the injection angle has a little effect on the airlift performance, but view the general conclusions as a whole, the best lifting efficiency can be obtained when the angle of the nozzle placed along the tangential direction of pipe wall is equal to 10º at a given air flow rate QG =37m3/h.

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Investigation of Circular and Shaped Effusion Cooling Arrays for Combustor Liner Application—Part 2: Numerical Analysis

Volume 3: Heat Transfer, Parts A and B ◽

10.1115/gt2009-60038 ◽

2009 ◽

Cited By ~ 2

Author(s):

A. Andreini ◽

C. Bianchini ◽

A. Ceccherini ◽

B. Facchini ◽

L. Mangani ◽

...

Keyword(s):

Numerical Analysis ◽

Cross Flow ◽

Lateral Spreading ◽

Elliptical Cross ◽

Injection Angle ◽

Blowing Ratio ◽

Combustor Liner ◽

Effectiveness Data ◽

Overall Effectiveness ◽

Good Agreement

A numerical analysis of two different effusion cooled plates, with a feasible arrangement for combustor liner application, is presented in this paper. Though having the same porosity and very shallow injection angle (17°), the first configuration presents a “conventional” circular drilling, while the other has “shaped” holes with such an elliptical cross-section that leads to a circular imprint on the cooled surface. Either geometries were the object of an experimental survey in which both adiabatic and overall effectiveness were measured. In order to compensate for the lack of detailed aerodynamic measurements, 3D CFD computations were performed for the two geometries. Steady state RANS calculations were carried out using a k–ε Two Layer turbulence model, both in the standard isotropic and in an algebraically corrected non isotropic version specifically tuned to better predict the lateral spreading of jets in a cross flow. Flow characteristic reproduce typical effusion cooled combustor liner conditions with blowing ratio of 5 and coolant jet Reynolds number of 12500. Even though good agreement could not be obtained comparing thermal adiabatic effectiveness with experiments, the findings of the experiments regarding the rating of the cooling efficiency of the two configurations were confirmed. Additionally, conjugate simulations were performed for the circular hole geometry in order to quantify heat transfer effects and to directly compare them with raw experimental overall effectiveness data.

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Numerical Investigation of Effects of Blockage, Inclination Angle, and Hole-Size on Film Cooling Effectiveness at Concave Surface

Journal of Turbomachinery ◽

10.1115/1.4049786 ◽

2021 ◽

Vol 143 (2) ◽

Author(s):

Fu-qiang Wang ◽

Jian Pu ◽

Jian-hua Wang ◽

Wei-dong Xia

Keyword(s):

Film Cooling ◽

Pressure Loss ◽

Numerical Study ◽

Density Ratio ◽

Concave Surface ◽

Blockage Ratio ◽

Coverage Area ◽

Cooling Effectiveness ◽

Film Cooling Effectiveness ◽

Injection Angle

Abstract Film-hole can be often blocked by thermal-barrier coatings (TBCs) spraying, resulting in the variations of aerodynamic and thermal performances of film cooling. In this study, a numerical study of the blockage effect on the film cooling effectiveness of inclined cylindrical-holes was carried out on a concave surface to simulate the airfoil pressure side. Three typical blowing ratios (BRs) of 0.5, 1.0, and 1.5 were chosen at an engine-similar density ratio (DR) of 2.0. Two common inclination angles of 30 deg and 45 deg were designed. The blockage ratios were adjusted from 0 to 20%. The results indicated the blockage could enhance the penetration of film cooling flow to the mainstream. Thus, the averaged effectiveness and coolant coverage area were reduced. Moreover, the pressure loss inside of the hole was increased. With the increase of BR, the decrement of film cooling effectiveness caused by blockage rapidly increased. At BR = 1.5, the decrement could be acquired up to 70% for a blockage ratio of 20%. The decrement of film cooling effectiveness caused by blockage was nearly nonsensitive to the injection angle; however, the larger angle could generate the higher increment of pressure loss caused by blockage. A new design method for the couple scheme of film cooling and TBC was proposed, i.e., increasing the inlet diameter according to the blockage ratio before TBC spraying. In comparison with the original unblocked-hole, the enlarged blocked-hole not only kept the nearly same area-averaged effectiveness but also reduced slightly the pressure loss inside of the hole. Unfortunately, application of enlarged blocked-hole at large BR could lead to a more obvious reduction of effectiveness near hole-exit, in comparison with the original common-hole.

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Numerical Analysis of Gas Turbine Inlet Fogging Nozzle Manifold Pressure Drop

Volume 3A: Coal, Biomass and Alternative Fuels; Cycle Innovations; Electric Power; Industrial and Cogeneration ◽

10.1115/gt2014-26497 ◽

2014 ◽

Author(s):

Hai Zhang ◽

Qun Zheng ◽

Mustapha Chaker ◽

Cyrus Meher-Homji

Keyword(s):

Pressure Drop ◽

Gas Turbine ◽

Flow Resistance ◽

Research Effort ◽

Water Injection ◽

Injection Velocity ◽

Injection Angle ◽

Turbine Inlet ◽

Area Of Concern ◽

Inlet Duct

The air pressure drop over the nozzles manifolds of inlet fogging system and the flow resistance downstream of the nozzle array (manifold) have always been an area of concern and is the object of this paper. Fogging nozzles arrays (involving several hundred nozzles) are mounted on channels and beams, downstream of the inlet filters and affect the pressure drop. The water injection angle, nozzle injection velocities and the progressive evaporation of the water droplets evaporation all influence the inlet pressure seen at the gas turbine inlet. This paper focuses on a numerical simulation investigation of flow resistance (pressure drop) of inlet fogging systems. In this research effort, the inlet duct is meshed in order to compute the pressure drop over the nozzles frames in fogging and non-fogging conditions. First, the resistance coefficients of an air intake filter are obtained by numerical and experimental methods, and then the coefficients are used for the simulation of the inlet duct by considering the filter as a porous media. Effects of nozzle spread pattern and water injection pattern are then modeled. The results indicate that injection velocity and arrangement of nozzles could have significant effects on the pressure drop and intake distortion, which will affect compressor performance. This paper provides a comprehensive analysis of the pressure drop and evaporation of inlet fogging and will be of value to gas turbine inlet fogging system designers and users.

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