Abstract: Temperature distribution investigation in a conical diffuser fitted with helical screw-tape with and without center-rod is studied numerically. A helical screw-tape is inserted in the diffuser to create swirl flow that helps to enhance the temperature distribution rate with inlet Reynolds number 4.3 x 104. Three pitch lengths ratios (Y/L = 0.153, 0.23 and 0.307) for the helical screw-tape with and without center-rod are simulated and compared. The geometry of the conical diffuser and the inlet condition for both arrangements are kept constant. Numerical findings show that the helical screw-tape inserts without center-rod perform significantly better than the helical tape inserts with center-rod in the conical diffuser.
Abstract: Combustion phenomenon will be accomplished
effectively by the development of low emission combustor. One of the
significant factors influencing the entire Combustion process is the
mixing between a swirling angular jet (Primary Air) and the
non-swirling inner jet (fuel). To study this fundamental flow, the
chamber had to be designed in such a manner that the combustion
process to sustain itself in a continuous manner and the temperature of
the products is sufficiently below the maximum working temperature
in the turbine. This study is used to develop the effective combustion
with low unburned combustion products by adopting the concept of
high swirl flow and motility of holes in the secondary chamber. The
proper selection of a swirler is needed to reduce emission which can be
concluded from the emission of Nox and CO2. The capture of CO2 is
necessary to mitigate CO2 emissions from natural gas. Thus the
suppression of unburned gases is a meaningful objective for the
development of high performance combustor without affecting turbine
blade temperature.
Abstract: Numerical study is performed to investigate the
temperature distribution in an annular diffuser fitted with helical tape
hub. Different pitches (Y = 20 mm, and Y = 30 mm) for the helical
tape are studied with different heights (H = 20 mm, 22 mm, and 24
mm) to be compared. The geometry of the annular diffuser and the
inlet condition for both hub arrangements are kept constant. The
result obtains that using helical tape insert with different pitches and
different heights will force the temperature to distribute in a helical
direction; however the use of helical tape hub with height (H = 22
mm) for both pitches enhance the temperature distribution in a good
manner.
Abstract: The influence of twist arrangement on the temperature
distribution in an annular diffuser fitted with twisted rectangular hub
is investigated. Different pitches (Y = 120 mm, 100 mm, 80 mm, and
60 mm) for the twist arrangements are simulated to be compared. The
geometry of the annular diffuser and the inlet condition for the hub
arrangements are kept constant. The result reveals that using twisted
rectangular hub insert with different pitches will force the
temperature to distribute in a circular direction. However,
temperature distribution will be enhanced with the length pitch
increases.
Abstract: In this research a comparison between k-epsilon and
LES model for a deoiling hydrocyclone is conducted. Flow field of
hydrocyclone is obtained by three-dimensional simulations with
OpenFOAM code. Potential of prediction for both methods of this
complex swirl flow is discussed. Large eddy simulation method
results have more similarity to experiment and its results are
presented in figures from different hydrocyclone cross sections.
Abstract: The objective of this work is to investigate the
turbulent reacting flow in a three dimensional combustor with
emphasis on the effect of inlet swirl flow through a numerical
simulation. Flow field is analyzed using the SIMPLE method which is
known as stable as well as accurate in the combustion modeling, and
the finite volume method is adopted in solving the radiative transfer
equation. In this work, the thermal and flow characteristics in a three
dimensional combustor by changing parameters such as equivalence
ratio and inlet swirl angle have investigated. As the equivalence ratio
increases, which means that more fuel is supplied due to a larger inlet
fuel velocity, the flame temperature increases and the location of
maximum temperature has moved towards downstream. In the mean
while, the existence of inlet swirl velocity makes the fuel and
combustion air more completely mixed and burnt in short distance.
Therefore, the locations of the maximum reaction rate and temperature
were shifted to forward direction compared with the case of no swirl.