Analysis of A Double Spiral Counter Flow Calorimeter in Impinging Flame Jet Using CFD Tool

Santosh Bagewadi et al. Int. Journal of Engineering Research and Applications www.ijera.com
ISSN : 2248-9622, Vol. 5, Issue 3, ( Part -5) March 2015, pp.54-59
www.ijera.com 54 | P a g e
Analysis of A Double Spiral Counter Flow Calorimeter in
Impinging Flame Jet Using CFD Tool
Santosh Bagewadi, A M Mulla, Dilip Sutraway
(Assistant Professor Department of Mechanical Engineering SECAB I E T Vijaypur, Karnataka, India-586101)
ABSTRACT
Enhancement of heat transfer rates in heat exchanger and calorimeter has been reported by many researchers.
However, work regarding heat transfer characteristics analysis of double spiral counter flow calorimeter is not
published and this forms the objective of this work. DSCFC is a unique design where it consists of single fluid as
working fluid for heat exchange. Here heat transfer takes place between solid and fluid, and hence can be called
as conjugate heat transfer problem. Heat transfer characteristics DSCFC is observed at various Reynolds number
and base temperature. DSCFC is analyzed considering conjugate heat transfer and temperature dependent
properties of heat transport media. Computations are performed using commercially available CFD package
ANSYS-CFX. It is observed that with increase in Reynolds number of the fluid, heat transfer reduces whereas
increase in base temperature increases heat transfer. The Computational results are compared with the
experimental.
Keywords: Double spiral calorimeter, Computational Fluid Dynamics, Conjugate heat transfer.
I. INTRODUCTION
A calorimeter is an object used for calorimetry,
or the process of measuring the physical changes as
well as heat capacity. The cooling or heating jacket
controls the temperature of the process. Heat is
measured by monitoring the heat gained or lost by the
heat transfer fluid. Constant flux calorimetry is
derived from heat balance calorimetry and uses
specialized control mechanisms to maintain a
constant heat flow (or flux) across the vessel wall.
Flame jet impingement heat transfer is a very
important process in industry and is used for many
applications like melting of scrap metal, shaping of
glass, welding, etc. Other advantage is that by this
method we can reduce the fuel consumption hence
we can increase the efficiency of the system of the
industry where heating is used. A lot of research
work has been carried in this area, both experimental
and numerical. Moreover, during practical analysis
the target surface is curved (i.e. cylindrical or
spherical). All experimental analysis where made by
taking the water as the cooling media, on copper or
brass plate and constant temperature boundary
condition where applied.
Double Spiral Counter Flow Calorimeter
(DSCFC) of constant flow area of 80 mm2 will be
used and the heat transfer takes place from flame to
calorimeter base plate/ target plate and then from
constant temperature base plate (isothermal) to spiral
flow water, it attains not only high heat transfer co-
efficient but also improved cooling uniformity and
maintain constant base plate temperature. In this
project a double spiral counter flow calorimeter set-
up is studied and it consists of spiral flow domain of
two concentric channels as shown in Figure 1. In a
DSCFC, the cold fluid enters inlet, flows inward and
comes out outward as hot fluid by absorbing the
energy from base plate.
Computational fluid dynamics is the branch of
fluid dynamics providing a cost effective means of
simulating real flows by the numerical solution of
governing equation. As a result of these factors,
Computational Fluid Dynamics is now an established
industrial design tool, helping to reduce design
timescales and improve processes throughout the
engineering world. CFD provides a cost-effective
and accurate alternative to scale model testing, with
variations on the simulation being performed quickly,
offering obvious advantages.
Fig.1 Double Spiral Counter Flow Calorimeter
RESEARCH ARTICLE OPEN ACCESS

II. Literature Review
Baukal et al [1] (1995) studied the targets were
used cylinders, flat plates and hemi-nosed cylinders.
Forced convection (laminar and turbulent) and
thermo-chemical heat release, have been the most
important heat transfer processes. Several semi-
analytic solutions have been developed, for the heat
flux to the forward stagnation point of a body of
revolution. These were originally developed for
aerospace applications, such as rocket re-entry into
the earth's atmosphere. These solutions, and many
variations, have been used to simulate flame
impingement heat transfer. The results of sample
calculations are compared to some of the
experimental measurement. Twelve flame
impingement experimental studies have been
considered here. In those studies, the measured heat
flux has been compared against one or more semi-
analytic solutions. Cylindrical, flat plate, and
hemisphere cylindrical targets have been used in one,
three, and nine studies respectively.
Baukal et al [2] (1997) reported on Surface
Condition Effects on Flame Impingement Heat
Transfer, This study investigated the heat transfer
from oxygen-enhanced, natural gas flames (15 kW)
impinging normal to a water-cooled metal disk (d b =
135 mm) segmented into concentric calorimetric
rings. Polished, untreated, and blackened surfaces
were used to study emissivity effects. The heat flux
to the blackened and polished surfaces was the
highest and lowest, respectively. The flux to
untreated surfaces was between the highest and
lowest fluxes. The largest difference in the flux,
between the polished and blackened surfaces, was
only 9.8%. Catalytic effects were investigated by
using alumina-coated (nearly non-catalytic),
untreated, and platinum-coated (highly catalytic)
surfaces. The heat flux to platinum-coated surfaces
was the highest. The fluxes to untreated surfaces
were similar to those for alumina-coated surfaces.
The largest difference in the flux, between the
platinum-coated and the alumina-coated surfaces,
was only 12%. Therefore, both non luminous flame
radiation and the thermo chemical heat release from
surface catalytic reactions were relatively small
fractions of the total heat flux. Inlet and outlet water
temperature measured, from which heat equation
were calculated.
Dong et al [3] (2003) studied the experimental
investigation of the flame shape and the heat transfer
and wall pressure characteristics of a pair of laminar
premixed butane/air flame jets impinging vertically
upon a horizontal water-cooled flat plate at jet
Reynolds numbers of 800, 1000 and 1200,
respectively. Equivalence ratio of the butane/air
mixture was maintained constantly at unity. The
flame shape, the pressure distribution on the
impingement plate and the heat transfer from the
flame to the plate were greatly influenced by the
interference occurred between the two flame jets.
This interference caused a sharp pressure peak at the
between-jet midpoint and the positive pressures at the
between-jet area, which led to the separation of the
wall jet from the impingement plate after collision.
The flame impingement surface was a square copper
plate of 200 mm long, 200 mm wide and 8 mm thick.
It was uniformly cooled on its backside by a cooling
water jacket. Copper was selected to fabricate the
plate because of its excellent thermal conductivity.
The top plate of the cooling water jacket was made of
Plexiglas to enable the water flow to be visualized. A
stainless steel frame was used to support the copper
plate and the cooling water jacket, so that the plate
could be placed either horizontally or tilted at a
selected angle relative to the burner. After a change
in the operating condition had been made,
measurements were only conducted after the steady-
state conditions had been established.
Shuhn-Shyurng Hou et al [4] (2003) studied the
measurements of temperature distributions, a water-
cooled stainless plate, 20 mm thick and 100 mm in
diameter, is used as the stagnation plane, as shown in
Fig. 1. The cooling water, supplied by a circulatory
(thermostatic water container), flows into the water-
cooled plate and removes the heat from the flame.
The thermal efficiency of an impinging flame is
defined as the percentage of the thermal input
transferred to the cooling water. Therefore, the
thermal efficiency equation can be determined by
measuring temperature difference between the inlet
and outlet cooling water,
Subhash Chander et al [5] (2005) used copper
plate of 8 mm thickness and 300 mm diameter as the
impingement surface. The surface of the plate was
smooth and it did not have any coating on it. There
was no soot deposition on the surface; still as
precaution it was periodically cleaned. A water jacket
was provided at the rear of the copper plate to evenly
cool the plate from the backside. Water flows into the
calorimeter at the center and comes out from the
calorimeter through the two exits provided at
diametrically opposite points. Inlet and outlet
temperatures of the water were measured with T type
thermocouples with full-scale accuracy of ±0.5%.
Tuttle et al [6] (2004) fabricated impingement
plate, measuring 71 cm square, with two layers of
aluminum plate separated by a rubber seal. The
bottom plate, made of 7075-T6 aluminum of
thickness 1.27 cm is exposed to the impinging flame,
with milled parallel grooves through which cooling
water flows. The flow of the cooling water was
regulated with three calibrated variable area flow
meters. Thermocouples were used to measure the
temperature of the water flowing in and out of the
plate to maintain the plate at a near-constant
temperature.

Kwok et al [7] (2004) studied three flame jets
impinged vertically upward onto a water-cooled
copper impingement plate having a surface area of
500 • 500 mm2 and a thickness of 8 mm. The cooling
water was kept at a temperature of 38oC by a
refrigerator to eliminate the condensation of water
vapour on the impingement plate surface. A heat flux
transducer having an effective sensing area of 6 mm2
was installed at the centre of the flame-side surface of
the impingement plate to measure the local heat flux
from the flame to the plate. By moving the three-
dimensional positioner horizontally in the x–y plane,
the local heat flux of a point on the impingement
plate relative to the stagnation point could be
measured, such that the heat flux distributions in the
x- and y directions of the impingement plate were
obtained. The heat flux received by the impingement
plate was reduced when the nozzle-to-plate distance
was increased.
Van Der Meer et al [8] (1991) studied the two
thermo-stated baths provided water flow of a constant
temperature. This flow was forced to pass through a
channel between a copper plate and a glass plate
separated by a small distance of 2.9 mm. The water
flowed along the copper plate into a reservoir behind
the plate and from that reservoir back into the first of
the two thermo-stated baths. In this way one side of
the glass plate was kept to a nearly constant
temperature provided the flow in the channel was
homogeneous and the heat transfer coefficient to the
glass plate very high. The temperature of the water
flowing through the channel was measured by
thermocouples. The other side of the glass plate was
covered with a thin layer of liquid crystals to measure
its surface temperature.
Jayakumara et al [9] (1997) studied heat transfer
characteristics of double pipe helical heat exchangers.
Heat transfer characteristics inside a helical coil for
various boundary conditions are compared. It is
found that the specification of a constant temperature
or constant heat flux boundary condition for an actual
heat exchanger does not yield proper modeling.
Hence, the heat exchanger is analyzed considering
conjugate heat transfer and temperature dependent
properties of heat transport media. Experimental
results are compared with the CFD calculation results
using the CFD package FLUENT 6.2. Based on the
experimental results a correlation is developed to
calculate the inner heat transfer coefficient of the
helical coil.
Achmad Nursyamsu [10] (2007) analyzing the
flow of water in a horizontal spiral pipe by
comparing the pitch distance 236 mm, 246 mm, 256
mm in a spiral pipe with a smooth surface. This is to
determine how far the effects of changes in pitch on
pressure drop are obtained and also to determine the
velocity vector of water flow in horizontal spiral pipe
using CFD method. By making a model of spiral pipe
and done meshing using hybrid simulation
configuration element type or tetrahedron, with
meshing the volume and size intervals of 5, and make
the boundary condition using the value V = 0.73 m / s
and Dh = 0032 m, so that pressure loss is obtained
and velocity at 246 mm pitch with a smaller decrease
in pressure (896.4 Pa) and the velocity distribution of
larger (max: 1.70 m / s, min: 5.39 x 10-2 m / S).
III. The solid modeling of DSCFC in
CFD-ICEM
Figure 2 shows the construction of spiral strip on
copper base plate, this strip forms a spiral flow
passage over the base plate. Figure-3 show the top
plate constructed on spiral strip, where adiabatic
boundary condition is applied
Fig-2 Base plate with spiral strip
Fig-3 complete model
Fig-4 Inlet flow position

Fig-5 outlet flow position
Boundary and Initial Conditions:
Since a finite flow domain is specified, physical
conditions are required on the boundaries of the flow
domain. The simulation generally starts from an
initial solution and uses an iterative method to reach a
final flow field solution. Boundary condition of
isothermal surface of the base plate and other
surfaces are adiabatic is considered for the present
study.
The simulation is performed with cfx solver with
various possible options for interactive or batch
processing and distributed processing.
IV. Results and Discussion
In this section results from the post processing
using CFD-POST is observed and represented. Plots
are plotted for parameters which are responsible for
performance of the double spiral counter flow
calorimeter. The following are some of the results
and discussion of the same.
For inlet fluid velocity of 0.057m/s (Re=199.6) and
base temperature of 343 ok. The pressure,
temperature and velocity profile are shown as
figure-6
Fig-6 pressure, temp and velocity profile
base temperature of 343o k. The pressure,
temperature and velocity profile are shown in
figure-7

Fig-7 pressure, temprature and velocity profile.
base temperature of 343o K. The pressure,
temperature and velocity profile as shown in
figure-8
Fig-8 pressure, temprature and velocity profile.
V. CONCLUSION:
For steady state analysis, the pressure drop for
calorimeter along the length of the flow is found to
be uniform except at the mid length and found to be
increasing with the Reynolds number. At the centre
of the plate there is sharp decline in pressure due to
change in the cross sectional area of flow. The
pressure recovery takes place in a short distance.
It is observed that temperature of water gradually
increased along the flow length because it picks up
heat during the course of the flow. There is a clear
evidence of the heat transfer cross the vertical strip
separating the adjacent counter flow hot and cold
steams.
For constant inlet and base temperatures, the out
let temperature of the water decreases with Reynolds
number.
Velocity suddenly increases at mid length due to
change in cross section area of DSCFC, velocity
recovers in a short distance in the downstream and
remains almost constant till the outlet.
There is no evidence of the influence of the base
temperature on the velocity distribution.
REFERENCES
[1] Baukal C.E. and Gebhart B. (1995) “A
review of semi-analytical solutions for flame
impingement heat transfer” Department of
Mechanical Engineering and Applied
Mechanics, University of Pennsylvania,
Philadelphia, PA 19104-6315, U.S.A
[2] Baukal C.E. and Gebhart B. (1997)
“Surface Condition Effects on Flame
Impingement Heat Transfer” Mechanical
Engineering and Applied Mechanics,
University of Pennsylvania, Philadelphia,
Pennsylvania
[3] Dong L.L, Leung C.W and Cheung C.S.
(2003) “Heat transfer and wall pressure

characteristics of a twin premixed
butane/air flame jets“ Department of
Mechanical Engineering, The Hong Kong
Polytechnic University.
[4] Shuhn-Shyurng Hou ,Yung-Chang Ko (2003)
“Effects of heating height on flame
appearance, temperature field and efficiency
of an impinging laminar jet flame used in
domestic gas stoves” Department of
Mechanical Engineering, Kun Shan
University of Technology, Tainan
[5] Subhash Chander, Anjan Ray (2005) “Heat
transfer characteristics of three interacting
methane/air flame jets impinging on a flat
surface” Department of Mechanical
Engineering, Indian Institute of Technology,
Delhi, New Delhi
[6] Tuttle S.G., Webb B.W and McQuay M.Q.
(2004) “Convective heat transfer from a
partially remixed impinging flame jet
“ Department of Mechanical Engineering,
Brigham Young University, Provo, United
States Received
[7] Kwok L.C., Leung C.W, Cheung C.S.
(2004) “Heat transfer characteristics of an
array of impinging pre-mixed slot flame jets”
Department of Mechanical Engineering, The
Hong Kong Polytechnic University,
[8] Van Der Meer T. H. (1991) “Stagnation
Point Heat Transfer from Turbulent Low
Reynolds Number Jets and Flame Jets”
Faculty of Applied Physics, Delft University
of Technology, Delft, The Netherlands
[9] Jayakumara J.S, Mahajania S.M., Mandala
J.C, Vijayanb P.K. (1997) “Experimental
and CFD estimation of heat transfer in
helically coiled heat exchangers”
[10] Achmad Nursyamsu (2007). “Analysis of
flow mal-distribution in tubular heat
exchangers by fluent” Department of
Mechanical Engineering National Institute
of Technology Rourkela.

Analysis of A Double Spiral Counter Flow Calorimeter in Impinging Flame Jet Using CFD Tool

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Analysis of A Double Spiral Counter Flow Calorimeter in Impinging Flame Jet Using CFD Tool