Three-dimensional Doppler Global Velocimetry in the flow of a fuel spray nozzle and in the wake region of a car

1996 ◽  
Vol 7 (3-4) ◽  
pp. 287-294 ◽  
Author(s):  
I. Roehle
Keyword(s):  
Three Dimensional ◽  
Fuel Spray ◽  
Spray Nozzle ◽  
Wake Region

Laminar Fluid Flow Around Two Wall-Mounted Blocks of Different Size

2009 ◽  
Author(s):  
Mohammad Mehdi Tavakol ◽  
Mohammad Eslami
Keyword(s):  
Fluid Flow ◽  
Free Stream ◽  
Three Dimensional ◽  
Simple Algorithm ◽  
Bluff Bodies ◽  
Wake Region ◽  
Science And Engineering ◽  
Vortical Structures ◽  
Laminar Fluid Flow ◽  
Pressure Distributions

Fluid flow around single or multiple bluff bodies mounted on a surface has great significance in science and engineering. Understanding the characteristics of different vortices formed around wall-mounted bodies is quite necessary for different applications. Although the case of a single surface mounted cube has been studied extensively, only little attention has been paid to the flow around two or more rectangular blocks in array. Therefore, a CFD code is developed to calculate three dimensional steady state laminar fluid flow around two cuboids of arbitrary size and configuration mounted on a surface in free stream conditions. The employed numerical scheme is finite volume and SIMPLE algorithm is used to treat pressure and velocity coupling. Results are presented for two rectangular blocks of the different size mounted on a surface in various inline arrangements. Streamlines are plotted for blocks of different size ratio. Velocity and pressure distributions are also plotted in the wake region behind the obstacles. It is shown that how the behavior of flow field and vortical structures depend on the respective size and location of the larger block in comparison with the case of two inline wall mounted cubes of the same size.

Part 2: Design Optimisation Strategies for a Fuel Spray Nozzle

2021 ◽  
Author(s):  
Thomas Andreou ◽  
Craig White ◽  
Konstantinos Kontis ◽  
Shahrokh Shahpar ◽  
Nicholas Brown
Keyword(s):  
Fuel Spray ◽  
Spray Nozzle ◽  
Design Optimisation

scholarly journals Evaporation Characteristics of Spray in a Lean Premixed-Prevaporization Combustor for a 100 KW Automotive Ceramic Gas Turbine

1994 ◽  
Author(s):  
Youichlrou Ohkubo ◽  
Yoshinorl Idota ◽  
Yoshihiro Nomura
Keyword(s):  
Gas Turbine ◽  
Mass Fraction ◽  
Liquid Fuel ◽  
Three Dimensional ◽  
Flame Stabilization ◽  
Fuel Spray ◽  
Inlet Temperature ◽  
Lean Combustion ◽  
Swirl Chamber ◽  
Lean Premixed

Spray characteristics of liquid fuel air-assisted atomizers developed for a lean premixed-prevaporization combustor were evaluated under two kinds of conditions: in still air under non-evaporation conditions at atmospheric pressure and in a prevaporization-premixing tube under evaporation conditions with a running gas turbine. The non-evaporated mass fraction of fuel spray was measured using a phase Doppler particle analyzer in the prevaporization-premixing tube, in which the inlet temperature ranged from 873K to 1173K. The evaporation of the fuel spray in the tube is mainly controlled by its atomization and distribution. The NOx emission characteristics measured with a combustor test rig were evaluated with three-dimensional numerical simulations. A low non-evaporated mass fraction of less than 10% was effective in reducing the exhausted NOx from lean premixed-prevaporization combustion to about 1/6 times smaller than that from lean diffusion (spray) combustion. The flow patterns in the combustor are established by a swirl chamber in fuel-air preparation tube, and affect the flame stabilization of lean combustion.

scholarly journals Two-scale dynamics of flow past a partial cross-stream array of tidal turbines

2013 ◽  
Vol 730 ◽  
pp. 220-244 ◽  
Author(s):  
Takafumi Nishino ◽  
Richard H. J. Willden
Keyword(s):  
Analytical Model ◽  
Three Dimensional ◽  
Navier Stokes ◽  
Wake Region ◽  
Near Wake ◽  
New Model ◽  
Tidal Turbines ◽  
Type Design ◽  
Flow Past ◽  
Far Wake

AbstractThe characteristics of flow past a partial cross-stream array of (idealized) tidal turbines are investigated both analytically and computationally to understand the mechanisms that determine the limiting performance of partial tidal fences. A two-scale analytical partial tidal fence model reported earlier is further extended by better accounting for the effect of array-scale flow expansion on device-scale dynamics, so that the new model is applicable to short fences (consisting of a small number of devices) as well as to long fences. The new model explains theoretically general trends of the limiting performance of partial tidal fences. The new model is then compared to three-dimensional Reynolds-averaged Navier–Stokes (RANS) computations of flow past an array of various numbers (up to 40) of actuator disks. On the whole, the analytical model agrees well with the RANS computations, suggesting that the two-scale dynamics described in the analytical model predominantly determines the fence performance in the RANS computations as well. The comparison also suggests that the limiting performance of short partial fences depends on how much of device far-wake mixing takes place within the array near-wake region. This factor, however, depends on the structures of the wake and therefore on the type/design of devices to be arrayed.

Implementation of the Axially Symmetrical and Three Dimensional Finite Element Models to the Determination of the Heat Transfer Coefficient Distribution on the Hot Plate Surface Cooled by the Water Spray Nozzle

2012 ◽  
Vol 504-506 ◽  
pp. 1055-1060 ◽  
Author(s):  
Zbigniew Malinowski ◽  
Tadeusz Telejko ◽  
Beata Hadala ◽  
Agnieszka Cebo-Rudnicka
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Three Dimensional ◽  
Spray Nozzle ◽  
Water Spray ◽  
Coefficient Distribution ◽  
The Heat Transfer Coefficient ◽  
Material Temperature

Plate and strip hot rolling lines are equipped with water cooling systems used to control the deformed material temperature. This system has a great importance in the case of thermal - mechanical deformation of steel which is focused on formation a proper microstructure and mechanical properties. The desired rate of cooling is achieved by water spray or laminar cooling applied to the hot surface of a strip. The water flow rate and pressure can be changed in a wide range and it will result in a very different heat transfer from the cooled material to the cooling water. The suitable cooling rate and the deformed material temperature can be determined based on numerical simulations. In this case thermal boundary conditions have to be specified on the cooled surface. The determination of the heat transfer coefficient distribution in the area of the water spray nozzle would improve numerical simulations significantly. In the paper an attempt is made to determine the heat transfer coefficient distribution on the hot plate surface cooled by the water spray nozzle. In the inverse method direct axially symmetrical and three dimensional solutions to the plate temperature field have been implemented. The computation time and the achieved accuracy have been compared for five cases. The studied cases differed in the maximum value of the heat transfer coefficient in nozzle spray axis and its distribution in the cooling time.

Three-dimensional numerical study of heat and mass transfer in fluidized beds with spray nozzle

2008 ◽  
Vol 32 (12) ◽  
pp. 2877-2890 ◽  
Author(s):  
Chamakuri Nagaiah ◽  
Gerald Warnecke ◽  
Stefan Heinrich ◽  
Mirko Peglow
Keyword(s):  
Mass Transfer ◽  
Heat And Mass Transfer ◽  
Fluidized Beds ◽  
Numerical Study ◽  
Three Dimensional ◽  
Spray Nozzle

The Research of Structural Optimization on Diesel Engine Injection Nozzle

2010 ◽  
Vol 97-101 ◽  
pp. 2571-2575
Author(s):  
Ming Hai Li ◽  
Hong Jiang Cui ◽  
Yun Dong Han ◽  
Ang Li
Keyword(s):  
Diesel Engine ◽  
Flow Field ◽  
Numerical Models ◽  
Three Dimensional ◽  
Injection Pressure ◽  
Injection System ◽  
Flow Structures ◽  
Spray Nozzle ◽  
Cad Cam ◽  
Flow Turbulence

In order to improve the performance of 16 V280 diesel engine, the three-dimensional numerical models of the flow field in the nozzle which belongs to the injection system was built, and different detailed flow structures was captured under different pressure conditions. Through the analysis of the flow field, the unsuitable position of the nozzle was located, and the methods which combine CAD / CAM / CFD was applicated to optimize the structure of the nozzle. The analysis results indicate that with the increase of the injection pressure; the flow turbulence intensity increases; the more energy get lost, which was caused by turbulence; the coefficient of flow decreases. After the spray nozzle structure was changed into sphere pin valve, the mass flux under the same level of injection pressure was improved greatly.

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