Experimentation to predict the thermal performance of closed loop pulsating heat pipe with acetone and methanol as working fluid
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The document discusses the thermal performance of a closed-loop pulsating heat pipe utilizing acetone and methanol as working fluids. It highlights the significance of filling ratio on performance, indicating that a 60% filling ratio yields optimal results. Experimental findings reveal that acetone demonstrates lower thermal resistance compared to methanol, enhancing the overall thermal efficiency of the heat pipe system.
![IJRET: International Journal of Research in Engineering and Technology eISSN: 2319-1163 | pISSN: 2321-7308
_______________________________________________________________________________________
Volume: 04 Issue: 04 | Apr-2015, Available @ http://www.ijret.org 23
EXPERIMENTATION TO PREDICT THE THERMAL PERFORMANCE
OF CLOSED LOOP PULSATING HEAT PIPE WITH ACETONE AND
METHANOL AS WORKING FLUID
Roshan D.Bhagat1
, K.M.Watt2
1
Student M.E.Thermal Engineering, Prof. Ram Meghe Institute of Technology & Research Badnera-Amravati, Sant
Gadge Baba Amravati University
2
Department of Mechanical Engineering, Prof. Ram Meghe Institute of Technology & Research Badnera-Amravati,
Sant Gadge Baba Amravati University
Abstract
The closed-loop pulsating heat pipe is a type of small heat transfer device with a very high thermal conductivity. It was invented
to meet the requirement for smaller heat transfer devices. It can transfer sufficient heat for heat dissipation applications in
modern electronic devices. The objective of this work is to study thermal performance of closed loop pulsating heat pipe with
acetone and methanol as working fluid.. Copper has been selected as material for heat pipe due to compatibility of copper with
acetone and methanol as working fluid. Filling ratio of the working fluid significantly influence on the performance closed loop
pulsating heat pipe. From the past studies it was observed that filling ratio of 30-75 % provides the best result hence 60 % filling
ratio has been selected for this filing ratio the thermal performance of closed loop pulsating heat pipe with acetone and methanol
as working fluid is investigate.
Keywords: closed loop pulsating heat pipe, condenser, evaporator, working fluid, filling ratio.
---------------------------------------------------------------------***-----------------------------------------------------------------
1. INTRODUCTION
The closed-loop pulsating heat pipe is a type of small heat
transfer device with a very high thermal conductivity. It was
invented to meet the requirement for smaller heat transfer
devices. It can transfer sufficient heat for heat dissipation
applications in modern electronic devices. The Closed loop
pulsating heat pipe is made of a long copper capillary tube,
bent into an undulating tube and connected at the ends to
form a closed-loop with no internal wick structure [1].
Working fluid is partially filled in the tube. The closed loop
pulsating heat pipe has a condenser, evaporator section and
adiabatic section. As any other two-phase passive thermal
control device, heat is acquired from the source through the
evaporator section transferring it to the working fluid where
the slug/plug pumping action will be generated. The fluid
then flows by the adiabatic section towards the condenser
section. On a closed loop configuration, the fluid is allowed
to circulate and after being condensed, the fluid returns to
the evaporator section to complete the loop. The tube is
evacuated and consequently partially filled with working
fluid. Since an inner diameter of the tube is very small and
then meets a capillary scale, the inside working fluid forms
into liquid slugs alternating with vapour slugs along the
entire length of the tube [2].
Fig 1: Closed loop pulsating heat pipe
When one end of the closed-loop pulsating heat pipe, called
„evaporator section‟, is subjected to heat or high
temperature, the working fluid, which is in liquid slug form,
will evaporate, expand, and move through the no heat
transferring zone, or „adiabatic section‟, toward a cooler
Section, „condenser section‟ . Then, the vapour slugs will
condense, collapse, and release the heat into the
environment. Therefore, the vapour slug evaporating in the
evaporator section will consequently flow to replace the
vapour slug collapsing in the condenser section. Due to this
mechanism, the working fluid can circulate and
continuously transfer heat in a cycle. The structure of the
closed loop pulsating heat pipe is as shown in Figure 1.](https://image.slidesharecdn.com/experimentationtopredictthethermalperformanceofclosedlooppulsatingheatpipewithacetoneandmethanolaswo-160903061845/85/Experimentation-to-predict-the-thermal-performance-of-closed-loop-pulsating-heat-pipe-with-acetone-and-methanol-as-working-fluid-1-320.jpg)
![IJRET: International Journal of Research in Engineering and Technology eISSN: 2319-1163 | pISSN: 2321-7308
_______________________________________________________________________________________
Volume: 04 Issue: 04 | Apr-2015, Available @ http://www.ijret.org 24
Table 1: Compatibility of closed loop pulsating heat pipe
material with the working fluid [2]
Working fluid Compatible Material
Methanol Stainless Steel, Iron, Copper, Brass,
Silica, Nickel
Acetone Stainless Steel, Copper, Brass, Silica
Table 2: Boiling point and operating ranges of working
fluid [2]
Working fluid Boiling point At 1
atm in K
Temperature
ranges in K
Acetone 329.4 273-393
Methanol 337.8 283-403
Ethanol 351.5 273-403
Fig 2: Experimental setup of closed loop pulsating heat pipe with acetone and methanol as working fluid
2. EXPERIMENTATION AND TESTING CLOSED LOOP PULSATING HEAT PIPE WITH ACETONE
AND METHANOL AS WORKING FLUID
Table 3: Evaporator temperature of closed loop pulsating heat pipe with methanol as working fluid at variable heat input
S.N VOLTAGE
(V)
CURRENT
(A)
HEAT
INPUT
(Watt)
EVAPORATOR TEMPERATURE
OF METHANOL 𝑰𝑵 𝟎
𝑪
AVERAGE
EVAPORATOR
TEMPERATURE
T1 T2 T3 T4 T5 T6
1 10 0.1 1 24.9 24.9 24.9 24.7 24.7 24.9 24.83333333
2 20 0.2 4 24.4 24.5 24.5 24.5 24.5 24.5 24.48333333
3 50 0.53 26.5 28.4 28.7 29 29 28.9 28.9 28.81666667
4 60 0.63 37.8 30.8 30.9 31 31 31 30.9 30.93333333
5 70 0.73 51.1 33.2 33.1 33.1 33.1 32.9 32.6 33
6 80 0.84 67.2 35.6 35.7 35.7 35.5 35.5 35.1 35.51666667
7 90 0.94 84.6 38.5 38.6 38.6 38.7 38.6 38.4 38.56666667
8 100 1.04 104 41.1 40.8 40.8 40.3 40.3 39.5 40.46666667
9 165 1.73 285.45 70.8 70.8 70.8 70.4 70.4 70.4 70.6
10 175 1.77 309.75 71.6 71.6 71 70.8 70.5 70.2 70.95
11 185 1.95 360.75 71.9 70.7 71.4 72.2 72.4 72 71.76666667
Table 4: Condenser temperature of closed loop pulsating heat pipe with methanol as working fluid at variable heat input
S.N VOLTAGE
(V)
CURRENT
(A)
HEAT
INPUT
(Watt)
CONDENSER TEMPERATURE
OF METHANOL 𝑰𝑵 𝟎
𝑪
AVERAGE
CONDENSER
TEMPERATURE
𝑇7 𝑇8 𝑇9 𝑇10 𝑇11 𝑇12
1 10 0.1 1 23.9 24 23.9 24 23.8 23.9 23.91666667
2 20 0.2 4 23.8 23.8 23.6 23.7 23.8 23.9 23.76666667](https://image.slidesharecdn.com/experimentationtopredictthethermalperformanceofclosedlooppulsatingheatpipewithacetoneandmethanolaswo-160903061845/85/Experimentation-to-predict-the-thermal-performance-of-closed-loop-pulsating-heat-pipe-with-acetone-and-methanol-as-working-fluid-2-320.jpg)
![IJRET: International Journal of Research in Engineering and Technology eISSN: 2319-1163 | pISSN: 2321-7308
_______________________________________________________________________________________
Volume: 04 Issue: 04 | Apr-2015, Available @ http://www.ijret.org 27
3. CONCLUSION
The thermal resistance of closed loop pulsating heat pipe
decreases with increase in the heat input for both methanol
and acetone hence the thermal performance of closed loop
pulsating heat pipe increases with increase in the heat input.
Also it was found from the experimental result that the
thermal resistance offered by closed loop pulsating heat pipe
with acetone as working fluid is comparatively less for the
same heat input as compared to closed loop pulsating heat
pipe with methanol as working fluid. Hence for the filling
ratio of 60 % closed loop pulsating heat pipe with acetone as
working fluid provides best thermal performance.
REFERENCES
[1] H. Akachi, F. Polasek, and P. Stulc, “Pulsating heat
pipes,” in Proc. 5th Intl. Heat Pipe Symp.,
Melbourne, Australia, 1996, pp. 208–217.
[2] M.B. Shafii, A. Faghri, Y. Zhang, Thermal modeling
of unlooped and looped pulsating heat pipes, ASME
J. Heat Transfer 123 (2001) 1159–1172.
[3] T. N. Wong, “High speed flow visualization of a
closed loop pulsating heat pipe,” Heat Mass Transfer,
vol. 48, pp. 3338–3351, 2005.
[4] N. Soponpongpipat, P. Sakulchangsatjatai, N.
Kammuang-lue, and P. Terdtoon, “Investigation of
the start up condition of a closed loop oscillating heat
pipe,” Heat Transfer Eng., vol. 30, no. 8, pp. 626–
642, 2009.
[5] Khandekar, S., Dollinger, N., Groll, M.,
“Understanding Operational Regimes of Closed Loop
Pulsating Heat Pipes: An Experimental Study”, 2003,
Applied Thermal Engineering, Vol. 23, pp.707-719.
[6] T. Mallikharjuna Rao, Dr. S. S. Rao, Heat Pipes for
Steam Condensation, IOSR Journal of Mechanical
and Civil Engineering (IOSR-JMCE) e-ISSN: 2278-
1684, ISSN: 2320-334X, Volume 11, Issue 2 Ver. I
(Mar- Apr. 2014), PP 16-19.
[7] M. Groll, S. Khandekar, Pulsating heat pipes,
Proceedings of the 3rd International Conference on
Transport Phenomena in Multiphase Systems, Kielce,
Poland, 2002, 35–44 (ISBN83-88906-03-08)
[8] S. Khandekar, M. Schneider, R. Kulenovic, M. Groll,
Thermofluid dynamic study of flat plate closed loop
pulsating heat pipes, Microsc. Thermophys. Eng. 6
(4) (2002) 303–318 (ISSN 1089-3954)
[9] Niti Kammuang-lue, Kritsada, Phrut
Sakulchangsatjatai, Pradit Terdtoon, Correlation to
Predict Thermal Performance According to Working
Fluids of Vertical Closed-Loop Pulsating Heat Pipe,
International Journal of Mechanical, Aerospace,
Industrial and Mechatronics Engineering Vol:8 No:5,
2014
[10] Zhang, Y., Faghri, A., “Heat Transfer in a Pulsating
Heat pipe with an Open End”, International Journal
of Heat and Mass Transfer, Vol. 45, 2002, pp. 755-
764.
[11] Nagvase S.Y. and Pachghare P.R.Parameters
Affecting the Functioning of Close Loop Pulsating
Heat Pipe:A Review ISSN 2278 – 9472, Vol. 2(1),
35-39, January (2013)
[12] Das, S.P., Nikolayev, V.S., Lefevre, F., Pottier, B.,
Khandekar, S. & Bonjour, J. Thermally induced two-
phase oscillating flow inside a capillary tube, Int. J.
Heat Mass Transfer, Vol. 53, pp. 3905-3913, 2010.
[13] Maydanik, Y.F., Dmitrin, V.I., Pastukhov, V.G.,
Compact cooler for electronics on the basis of a
pulsating heat pipe, Appl. Therm. Eng., 29 (17-18),
pp. 3511-3517, 2009.
[14] Zhang, Y. and Faghri, A. Advances and unsolved
issues in pulsating heat pipes, Int. J. Heat Mass
Transfer 45 (4), pp. 755-764, 2002.](https://image.slidesharecdn.com/experimentationtopredictthethermalperformanceofclosedlooppulsatingheatpipewithacetoneandmethanolaswo-160903061845/85/Experimentation-to-predict-the-thermal-performance-of-closed-loop-pulsating-heat-pipe-with-acetone-and-methanol-as-working-fluid-5-320.jpg)
Experimentation to predict the thermal performance of closed loop pulsating heat pipe with acetone and methanol as working fluid
- 1. IJRET: International Journal of Research in Engineering and Technology eISSN: 2319-1163 | pISSN: 2321-7308 _______________________________________________________________________________________ Volume: 04 Issue: 04 | Apr-2015, Available @ http://www.ijret.org 23 EXPERIMENTATION TO PREDICT THE THERMAL PERFORMANCE OF CLOSED LOOP PULSATING HEAT PIPE WITH ACETONE AND METHANOL AS WORKING FLUID Roshan D.Bhagat1 , K.M.Watt2 1 Student M.E.Thermal Engineering, Prof. Ram Meghe Institute of Technology & Research Badnera-Amravati, Sant Gadge Baba Amravati University 2 Department of Mechanical Engineering, Prof. Ram Meghe Institute of Technology & Research Badnera-Amravati, Sant Gadge Baba Amravati University Abstract The closed-loop pulsating heat pipe is a type of small heat transfer device with a very high thermal conductivity. It was invented to meet the requirement for smaller heat transfer devices. It can transfer sufficient heat for heat dissipation applications in modern electronic devices. The objective of this work is to study thermal performance of closed loop pulsating heat pipe with acetone and methanol as working fluid.. Copper has been selected as material for heat pipe due to compatibility of copper with acetone and methanol as working fluid. Filling ratio of the working fluid significantly influence on the performance closed loop pulsating heat pipe. From the past studies it was observed that filling ratio of 30-75 % provides the best result hence 60 % filling ratio has been selected for this filing ratio the thermal performance of closed loop pulsating heat pipe with acetone and methanol as working fluid is investigate. Keywords: closed loop pulsating heat pipe, condenser, evaporator, working fluid, filling ratio. ---------------------------------------------------------------------***----------------------------------------------------------------- 1. INTRODUCTION The closed-loop pulsating heat pipe is a type of small heat transfer device with a very high thermal conductivity. It was invented to meet the requirement for smaller heat transfer devices. It can transfer sufficient heat for heat dissipation applications in modern electronic devices. The Closed loop pulsating heat pipe is made of a long copper capillary tube, bent into an undulating tube and connected at the ends to form a closed-loop with no internal wick structure [1]. Working fluid is partially filled in the tube. The closed loop pulsating heat pipe has a condenser, evaporator section and adiabatic section. As any other two-phase passive thermal control device, heat is acquired from the source through the evaporator section transferring it to the working fluid where the slug/plug pumping action will be generated. The fluid then flows by the adiabatic section towards the condenser section. On a closed loop configuration, the fluid is allowed to circulate and after being condensed, the fluid returns to the evaporator section to complete the loop. The tube is evacuated and consequently partially filled with working fluid. Since an inner diameter of the tube is very small and then meets a capillary scale, the inside working fluid forms into liquid slugs alternating with vapour slugs along the entire length of the tube [2]. Fig 1: Closed loop pulsating heat pipe When one end of the closed-loop pulsating heat pipe, called „evaporator section‟, is subjected to heat or high temperature, the working fluid, which is in liquid slug form, will evaporate, expand, and move through the no heat transferring zone, or „adiabatic section‟, toward a cooler Section, „condenser section‟ . Then, the vapour slugs will condense, collapse, and release the heat into the environment. Therefore, the vapour slug evaporating in the evaporator section will consequently flow to replace the vapour slug collapsing in the condenser section. Due to this mechanism, the working fluid can circulate and continuously transfer heat in a cycle. The structure of the closed loop pulsating heat pipe is as shown in Figure 1.
- 2. IJRET: International Journal of Research in Engineering and Technology eISSN: 2319-1163 | pISSN: 2321-7308 _______________________________________________________________________________________ Volume: 04 Issue: 04 | Apr-2015, Available @ http://www.ijret.org 24 Table 1: Compatibility of closed loop pulsating heat pipe material with the working fluid [2] Working fluid Compatible Material Methanol Stainless Steel, Iron, Copper, Brass, Silica, Nickel Acetone Stainless Steel, Copper, Brass, Silica Table 2: Boiling point and operating ranges of working fluid [2] Working fluid Boiling point At 1 atm in K Temperature ranges in K Acetone 329.4 273-393 Methanol 337.8 283-403 Ethanol 351.5 273-403 Fig 2: Experimental setup of closed loop pulsating heat pipe with acetone and methanol as working fluid 2. EXPERIMENTATION AND TESTING CLOSED LOOP PULSATING HEAT PIPE WITH ACETONE AND METHANOL AS WORKING FLUID Table 3: Evaporator temperature of closed loop pulsating heat pipe with methanol as working fluid at variable heat input S.N VOLTAGE (V) CURRENT (A) HEAT INPUT (Watt) EVAPORATOR TEMPERATURE OF METHANOL 𝑰𝑵 𝟎 𝑪 AVERAGE EVAPORATOR TEMPERATURE T1 T2 T3 T4 T5 T6 1 10 0.1 1 24.9 24.9 24.9 24.7 24.7 24.9 24.83333333 2 20 0.2 4 24.4 24.5 24.5 24.5 24.5 24.5 24.48333333 3 50 0.53 26.5 28.4 28.7 29 29 28.9 28.9 28.81666667 4 60 0.63 37.8 30.8 30.9 31 31 31 30.9 30.93333333 5 70 0.73 51.1 33.2 33.1 33.1 33.1 32.9 32.6 33 6 80 0.84 67.2 35.6 35.7 35.7 35.5 35.5 35.1 35.51666667 7 90 0.94 84.6 38.5 38.6 38.6 38.7 38.6 38.4 38.56666667 8 100 1.04 104 41.1 40.8 40.8 40.3 40.3 39.5 40.46666667 9 165 1.73 285.45 70.8 70.8 70.8 70.4 70.4 70.4 70.6 10 175 1.77 309.75 71.6 71.6 71 70.8 70.5 70.2 70.95 11 185 1.95 360.75 71.9 70.7 71.4 72.2 72.4 72 71.76666667 Table 4: Condenser temperature of closed loop pulsating heat pipe with methanol as working fluid at variable heat input S.N VOLTAGE (V) CURRENT (A) HEAT INPUT (Watt) CONDENSER TEMPERATURE OF METHANOL 𝑰𝑵 𝟎 𝑪 AVERAGE CONDENSER TEMPERATURE 𝑇7 𝑇8 𝑇9 𝑇10 𝑇11 𝑇12 1 10 0.1 1 23.9 24 23.9 24 23.8 23.9 23.91666667 2 20 0.2 4 23.8 23.8 23.6 23.7 23.8 23.9 23.76666667
- 3. IJRET: International Journal of Research in Engineering and Technology eISSN: 2319-1163 | pISSN: 2321-7308 _______________________________________________________________________________________ Volume: 04 Issue: 04 | Apr-2015, Available @ http://www.ijret.org 25 3 50 0.53 26.5 24 24 24.1 24.3 24.3 24.5 24.2 4 60 0.63 37.8 24.9 24.8 24.8 24.8 24.8 24.6 24.78333333 5 70 0.73 51.1 24.5 24.6 25.2 25.2 25.2 25.3 25 6 80 0.84 67.2 25.3 25.3 25.4 25.4 25.4 25.5 25.38333333 7 90 0.94 84.6 25.3 25.8 26 26 26 26.1 25.86666667 8 100 1.04 104 26.1 25.9 26.1 26 26 26.2 26.05 9 165 1.73 285.45 33.5 33.3 32.3 31 30.2 30.1 31.73333333 10 175 1.77 309.75 34 33.5 33 30.9 30.1 30.1 31.93333333 11 185 1.95 360.75 33.8 33.6 33.6 31.2 30.8 30.1 32.18333333 Table 5: Condenser temperature of closed loop pulsating heat pipe with acetone as working fluid at variable heat input S.N VOLTAGE (V) CURRENT (A) HEAT INPUT (Watt) CONDENSER TEMPERATURE ACETONE 𝐼𝑁0 𝐶 AVERAGE CONDENSER TEMPERATURE 𝑻 𝟕 𝑻 𝟖 𝑻 𝟗 𝑻 𝟏𝟎 𝑻 𝟏𝟏 𝑻 𝟏𝟐 1 10 0.1 1 25.8 26 25.8 26.1 25.8 26.1 25.93333333 2 20 0.2 4 25.8 25.9 25.8 25.8 25.7 25.9 25.81666667 3 50 0.53 26.5 25.5 25.5 25.5 25.5 25.3 25.5 25.46666667 4 60 0.63 37.8 25 25.1 25 25 25 25 25.01666667 5 70 0.73 51.1 25.2 25.1 25 24.9 25 25.2 25.06666667 6 80 0.84 67.2 25.5 25.5 25.5 25.5 25.2 25.3 25.41666667 7 90 0.94 84.6 26.4 26.4 26.4 26.1 25.9 25.7 26.15 8 100 1.04 104 26.9 27 27.2 27.3 27.3 27 27.11666667 9 165 1.73 285.45 31.7 32.6 32.9 32.7 31.7 30.6 32.03333333 10 175 1.77 309.75 32.4 32.3 32.5 32.5 32 30.7 32.06666667 11 185 1.95 360.75 33 33.2 33.2 32.8 32.8 30.7 32.61666667 Table 6: Evaporator temperature of closed loop pulsating heat pipe with acetone as working fluid at variable heat input S.N VOLTAGE (V) CURRENT (A) HEAT INPUT (Watt) EVAPORATOR TEMPERATURE ACETONE 𝐼𝑁0 𝐶 AVERAGE EVAPORATOR TEMPERATURE𝑻 𝟏 𝑻 𝟐 𝑻 𝟑 𝑻 𝟒 𝑻 𝟓 𝑻 𝟔 1 10 0.1 1 26 26.1 25.8 26 26.1 25.9 25.98333333 2 20 0.2 4 26 26.1 25.9 25.7 25.5 25.8 25.83333333 3 50 0.53 26.5 29 29 29 29.1 29.1 29.2 29.06666667 4 60 0.63 37.8 30 30.1 30.2 30.2 30.1 30.1 30.11666667 5 70 0.73 51.1 31.8 31.7 31.7 31.6 31.7 31.7 31.7 6 80 0.84 67.2 34 33.9 33.9 33.9 33.9 33.8 33.9 7 90 0.94 84.6 36.9 36.9 36.9 36.6 36.7 36.6 36.76666667 8 100 1.04 104 39.9 40.2 40.2 40.2 40.2 40.2 40.15 9 165 1.73 285.45 65.1 65.1 65.1 65.1 65.1 65.1 65.1 10 175 1.77 309.75 66.5 66.5 66.8 67.1 67.1 67.1 66.85 11 185 1.95 360.75 68.7 68.7 68.7 68.5 68.5 68.8 68.65
- 4. IJRET: International Journal of Research in Engineering and Technology eISSN: 2319-1163 | pISSN: 2321-7308 _______________________________________________________________________________________ Volume: 04 Issue: 04 | Apr-2015, Available @ http://www.ijret.org 26 Table 7: Thermal resistance of closed loop pulsating heat pipe with acetone and methanol as working fluid at variable heat input S.N HEAT INPUT (Watt) FOR ACETONE THERMAL RESISTANCE OF ACETONE THERMAL RESISTANCE OF METHANOL 1 1 0.05 0.916666667 2 4 0.004166667 0.179166667 3 26.5 0.135849057 0.174213836 4 37.8 0.134920635 0.162698413 5 51.1 0.129810828 0.156555773 6 67.2 0.126240079 0.150793651 7 84.6 0.125492514 0.150118203 8 104 0.125320513 0.138621795 9 285.45 0.115840486 0.136159281 10 309.75 0.112294861 0.125961797 11 360.75 0.0998845 0.10972511 Fig 3: Evaporator and condenser temperature of closed loop pulsating heat pipe with acetone and methanol as working fluid at variable heat input Fig 4: Thermal resistance of closed loop pulsating heat pipe with acetone and methanol as working fluid at variable heat input 0 10 20 30 40 50 60 70 80 Temperature Heat Input (Watt) TE(M) TC(M) TE(A) TC(A) 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 ThermalResistance Heat Input (Watt) Methanol Acetone
- 5. IJRET: International Journal of Research in Engineering and Technology eISSN: 2319-1163 | pISSN: 2321-7308 _______________________________________________________________________________________ Volume: 04 Issue: 04 | Apr-2015, Available @ http://www.ijret.org 27 3. CONCLUSION The thermal resistance of closed loop pulsating heat pipe decreases with increase in the heat input for both methanol and acetone hence the thermal performance of closed loop pulsating heat pipe increases with increase in the heat input. Also it was found from the experimental result that the thermal resistance offered by closed loop pulsating heat pipe with acetone as working fluid is comparatively less for the same heat input as compared to closed loop pulsating heat pipe with methanol as working fluid. Hence for the filling ratio of 60 % closed loop pulsating heat pipe with acetone as working fluid provides best thermal performance. REFERENCES [1] H. Akachi, F. Polasek, and P. Stulc, “Pulsating heat pipes,” in Proc. 5th Intl. Heat Pipe Symp., Melbourne, Australia, 1996, pp. 208–217. [2] M.B. Shafii, A. Faghri, Y. Zhang, Thermal modeling of unlooped and looped pulsating heat pipes, ASME J. Heat Transfer 123 (2001) 1159–1172. [3] T. N. Wong, “High speed flow visualization of a closed loop pulsating heat pipe,” Heat Mass Transfer, vol. 48, pp. 3338–3351, 2005. [4] N. Soponpongpipat, P. Sakulchangsatjatai, N. Kammuang-lue, and P. Terdtoon, “Investigation of the start up condition of a closed loop oscillating heat pipe,” Heat Transfer Eng., vol. 30, no. 8, pp. 626– 642, 2009. [5] Khandekar, S., Dollinger, N., Groll, M., “Understanding Operational Regimes of Closed Loop Pulsating Heat Pipes: An Experimental Study”, 2003, Applied Thermal Engineering, Vol. 23, pp.707-719. [6] T. Mallikharjuna Rao, Dr. S. S. Rao, Heat Pipes for Steam Condensation, IOSR Journal of Mechanical and Civil Engineering (IOSR-JMCE) e-ISSN: 2278- 1684, ISSN: 2320-334X, Volume 11, Issue 2 Ver. I (Mar- Apr. 2014), PP 16-19. [7] M. Groll, S. Khandekar, Pulsating heat pipes, Proceedings of the 3rd International Conference on Transport Phenomena in Multiphase Systems, Kielce, Poland, 2002, 35–44 (ISBN83-88906-03-08) [8] S. Khandekar, M. Schneider, R. Kulenovic, M. Groll, Thermofluid dynamic study of flat plate closed loop pulsating heat pipes, Microsc. Thermophys. Eng. 6 (4) (2002) 303–318 (ISSN 1089-3954) [9] Niti Kammuang-lue, Kritsada, Phrut Sakulchangsatjatai, Pradit Terdtoon, Correlation to Predict Thermal Performance According to Working Fluids of Vertical Closed-Loop Pulsating Heat Pipe, International Journal of Mechanical, Aerospace, Industrial and Mechatronics Engineering Vol:8 No:5, 2014 [10] Zhang, Y., Faghri, A., “Heat Transfer in a Pulsating Heat pipe with an Open End”, International Journal of Heat and Mass Transfer, Vol. 45, 2002, pp. 755- 764. [11] Nagvase S.Y. and Pachghare P.R.Parameters Affecting the Functioning of Close Loop Pulsating Heat Pipe:A Review ISSN 2278 – 9472, Vol. 2(1), 35-39, January (2013) [12] Das, S.P., Nikolayev, V.S., Lefevre, F., Pottier, B., Khandekar, S. & Bonjour, J. Thermally induced two- phase oscillating flow inside a capillary tube, Int. J. Heat Mass Transfer, Vol. 53, pp. 3905-3913, 2010. [13] Maydanik, Y.F., Dmitrin, V.I., Pastukhov, V.G., Compact cooler for electronics on the basis of a pulsating heat pipe, Appl. Therm. Eng., 29 (17-18), pp. 3511-3517, 2009. [14] Zhang, Y. and Faghri, A. Advances and unsolved issues in pulsating heat pipes, Int. J. Heat Mass Transfer 45 (4), pp. 755-764, 2002.