1. Optimization of effectiveness of Stirling engine
regenerators using different materials
Members: Muhammad Umer, Rana Majid, Nouman Ramzan
Advisor: Nauman Javed
Introduction:
• A Stirling engine is a closed-cycle
regenerative external combustion heat engine,
that operates by cyclic compression and
expansion of air or other gas (the working
fluid) at different temperatures, such that
there is a net conversion of heat energy to
mechanical work or vice versa.
• It is an external combustion engine that use
any source of heat like forest waste, biogas,
solar heat and electricity.
• Regenerative describes the use of a specific
type of internal heat exchanger and thermal
store, known as the regenerator.
Objectives:
• Design and fabrication of Stirling engine.
• Designing and fabrication of a heat source for
Stirling engine.
• Design and fabrication of regenerators of
different materials.
• Comparison of Stirling engine efficiencies by
using different regenerators.
Methodology:
• Torque measurement using hydraulic
dynamometer ( minimum torque value: 0.005
Nm) available at Automotive Center UET,
Lahore.
• Speed measurement using non contact
tachometer minimum speed value: 0.01 RPM)
• Power calculations using torque and speed .
• Fabrication of regenerators using different
porosities (75% to 90% ) and number of
screens of wire mesh of Aluminum, copper,
stainless steel.
• Re calculate power using fabricated
regenerators.
• Effeciency calculations of Stirling engine.
Engine Model:
Experimentation:
Fig1: 3D Design Model of Alpha Stirling Engine
Fig2: 3D Practical Model of Alpha Stirling Engine
Table1:Experimental Results:
Fig4: Solar powered experimentation
1.Mounir B. Ibrahim and Roy C. Tew, Stirling Converter Regenerators. New York: CRC Press, 2011.
2.Graham Walker, Stirling Engines. New York, USA: Oxford University Press, 1980.References:
Summary:
Even small changes in regenerator volumes
can produce substantial changes in power
output, heat input and efficiency. The
optimum values obtained were:
• Diameter: 3.5 cm
• Porosity: 3 wires/cm
• Net power: 74.18 Watts
• Efficiency: 13.1%
Fig5: Effect of diameter on
power and efficiency
Fig6: Effect of porosity on
power and efficiency
Fig7: Effects on dead volume
Application:
• As a prime mover.
• As a refrigerating machine.
• As a heat pump.
• This can be used as a standalone system in the
deserted areas of Pakistan like Thar for the
electricity generation and for extracting of
clean water from ground.
Fig3: Electric power experimentation