Journal of Mechanical Science and Technology

, Volume 33, Issue 4, pp 1907–1914 | Cite as

Thermal characteristics of an ammonia-charged closed-loop pulsating heat pipe

  • Md Shahidul Haque
  • Antara Majumdar
  • Md. Faisal Kader
  • Md. Mahbubur RazzaqEmail author


At this age, engineering applications are demanding effective ways of heat recovery and energy savings for their optimum performance. Among other cooling techniques, pulsating heat pipes have emerged as a convenient and cost effective thermal design solution due to its excellent heat transfer capability, high thermal efficiency and structural simplicity. The paper presents an experimental study on the operational limit of an aluminum closed-loop pulsating heat pipe (CLPHP) charged with ammonia. It consists of total 14 turns of aluminum pipe with 3 mm inner and 4 mm outer diameter. Ammonia was used as working fluid with 3 different filling ratios such as 0.4, 0.6 and 0.8. Operation orientations were vertical, 30°, 45°, 60°, 90° and 180° inclinations. Constant electric heat input of 36 W was applied to the heating block and temperature rise in various sections was monitored till steady state was reached. Temperature was measured at different locations of the CLPHP by using thermocouples. The effects of operational orientations and filling ratios were investigated on heat transfer by working fluid php (Watt), overall heat transfer coefficient U (W/m2 °C) and thermal resistance R (°C/W) considering the measured temperature. The result shows that, 0.4 and 0.6 fill ratios and inclination angle of 30º give better result than any other arrangements for CLPHP.


Closed loop pulsating heat pipe (CLPHP) Fill ratio Overall heat transfer co-efficient Thermal resistance 


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Copyright information

© KSME & Springer 2019

Authors and Affiliations

  • Md Shahidul Haque
    • 1
  • Antara Majumdar
    • 1
  • Md. Faisal Kader
    • 1
  • Md. Mahbubur Razzaq
    • 2
    Email author
  1. 1.Department of Mechanical EngineeringBangladesh Military AcademyBhatiay, ChittagongBangladesh
  2. 2.Department of Mechanical EngineeringBangladesh University of Engineering and TechnologyDhakaBangladesh

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