Numerical simulation is performed in this study to explore film-cooling enhancement by injecting mist into the cooling air with a focus on investigating effect of various modeling schemes results. The turbulence models, dispersed-phase modeling, inclusion different forces (Saffman, thermophoresis, and Brownian), trajectory tracking, injection scheme studied. flow inlet boundary conditions (with/without supply plenum), intensity, near-wall grid density results also included. Simulation...

When pulling a particle in driven granular fluid with constant force $F_{ex}$, the probe approaches steady-state average velocity $v$. This and corresponding friction coefficient of $\zeta=F_{ex}/v$ are obtained within schematic model mode-coupling theory compared to results from event-driven simulations. For small moderate drag forces, describes simulation successfully for both linear as well nonlinear region: The response regime (constant friction) forces is followed by shear thinning...

The output and efficiency of gas turbines are reduced significantly during the summer. Gas turbine inlet air-cooling is considered a simple effective method to increase power as well thermal efficiency. Among various cooling schemes, fog (a direct evaporative cooling) has gained increasing popularity due its simplicity low installation cost. During cooling, water atomized micro-scaled droplets (or mist) introduced into airflow. air temperature through evaporation. To investigate mist...

A stage-by-stage wet-compression theory and algorithm have been developed for overspray interstage fogging in the compressor. This are used to calculate performance of an 8-stage compressor under both dry wet compressions. 2D airfoil geometry stage setting at mean radius employed. Six different cases with without investigated compared. The pressure ratio enhances during all as does overall ratio, saturated (no overspray) achieving highest ratio. Saturated reduces specific work, but increases...

Compressor intercooling has traditionally been employed to reduce compressor work and augment gas turbine output power. Conventional schemes are usually applied through non-mixed heat exchangers between two stages or by cooling the outside of casing. Any that may affect flow field inside compressors have not favorably considered due concerns any disturbance might adversely compressor’s performance stability. As inlet fog scheme become popular as an economic effective means power on hot dry...

This first part of the paper presents techniques implemented for experimental investigation transition mechanism in 2-D pressure driven separated boundary layer flows over a flat plate at inlet free-stream turbulence intensities ranging from 0.3 to 0.6% and imposed adverse gradients K = − 0.68 × 10−6 6.25 10−6. The structure behavior separation bubble were investigated various flow conditions. separated-flow modes identified classified. distribution end strength gradient obtained by varying...

Purpose This study focused on how to realize automatic recognition of young women's neck-shoulder shape based the front and side images. Design/methodology/approach The reverse engineering software was used measure body sizes part three-dimensional (3D) point cloud data, important parameters closely related were determined. subjects classified establish classification rules. Then, images, human contour extracted by Matlab, data required for obtained identifying feature points. Findings...

This paper clearly identifies the possible modes of transition in separated boundary layers and their specific characteristics. study distinguishes between short long bubbles primarily based on flow structure. A hypothetical description vortex structure evolution for each separated-flow mode is provided. The present approach analyzing assumption that to turbulence a result superposition effects two different types instability. first type instability Kelvin-Helmholtz (KH) It occurs develops...

The output and efficiency of gas turbines are reduced significantly during the summer. Gas turbine inlet air-cooling is considered a simple effective method to increase power as well thermal efficiency. Among various cooling schemes, fog (a direct evaporative cooling) has gained increasing popularity due its simplicity low installation cost. During cooling, water atomized micro-scaled droplets (or mist) introduced into airflow. air temperature through evaporation. To investigate mist...

The passive sweeping jet fluidic oscillators are a promising potential candidate in heat transfer applications such as gas turbine cooling, electronic components and exchanger enhancement component. This review presents detailed discussion, summary, comparison of the studies on jets. Sweeping jets can be created by two different types (i.e., wall-attachment type interaction type). Those do not need moving part nor active control to create In type, fluid enters oscillator, fills cavity...

The present paper focuses on presenting the results of experimental investigation transition process in separated boundary layers a flat plate at zero incidence, with imposed adverse pressure gradients. combined effects Reynolds number and gradient strength mechanism, bubble geometry, bursting are studied. flow structures unsteady aspects associated separated-flow analyzed for three representative cases. Surface detailed layer measurements using hot-wire anemometry presented as mean rms...

The present study formulates an improved approach for analyzing separated-flow transition that differentiates between the process in boundary layers which are laminar at separation and those already transitional separation. paper introduces new parameters necessary classifying modes accounting concomitant evolution of separated shear layer average effect periodic bubble build-up vortex shedding. At least three positively distinguished: (a) separation, with starting upstream point developing...

A Phase Doppler Particle Analyzer (PDPA) system is employed to measure the two-phase mist flow behavior including velocity field, droplet size distribution, dynamics, and turbulence characteristics. Based on measurements made through PDPA, a projected profile describing how air-mist coolant jet spreads eventually blends into hot main proposed. This proposed found be well supported by measurement results of turbulent Reynolds stresses. The film envelope identified with shear layers...

Calcined coke is an important material for making carbon anodes smelting alumina to aluminum. Calcining energy intensive industry and a significant amount of heat wasted in the calcining process. Efficiently managing this resource tied profit margin survivability plant. To help improve efficiency process, 3D computational model developed gain insight thermal-flow combustion behavior calciner. Comprehensive models are employed simulate moving petcoke bed with moisture evaporation,...

The output and efficiency of gas turbines are reduced significantly during the summer, especially in areas where daytime temperature reaches as high 50°C. Gas turbine inlet fogging overspray has been considered a simple cost-effective method to increase power output. One most important issues related is determine effective location device by determining (a) how many water droplets actually evaporate effectively cool down air instead colliding on wall or coalescing draining out (i.e....