TA Engine Mid term Presentation By Subhan

8/10/2019 TA Engine Mid term Presentation By Subhan

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Thermoacoustic Engine

Mid term presentation

Advisor: Prof. Akiyoshi Iida

Assistant Prof. Hiroshi Yokoyama

Student: Subhan Ullah

Student ID: M135117



Table of contents

• Background

• Objective

• Previous research

• Objective

• Experimental setup

• Results

• Conclusion

• Future plan

10/23/2014 Mid term Presentation 2



Background

Sound power amplification

Cooling

RegeneratorHeater

Soundwaves

Thermoacoustic

oscillations

Heat Thermoacousticwork

Thermoacoustic

Engine

Backhaus, S. et al. Nature (1999)

Advantages:• No moving parts

– Maintenance is

cheap

• Environment friendly

– The working fluid is

helium and air

• Very simple andcheap




Objective

• To understand the characteristics of the

loop-shaped double stage and single

stage Thermoacoustic engine

– Oscillation temperature ratio TH/TR

– Energy efficiency

– Pressure amplitude, Velocity amplitude and

the acoustic work




Previous research

• ‘‘Thermoacoustics,’’ Nikolaus Rott [Adv. Appl. Mech. 20,

135 –175(1980)]. This article summarizes Rott’s theory of

heat-driven acoustic oscillations and streaming

developed through a series of articles published in Z.

Angew. Math. Phys. starting in 1969. That work providedthe theoretical foundation for the growth of

thermoacoustics that started shortly after the publication

of Rott’s review.

• ‘‘Thermoacoustic engines,’’ G. W. Swift, J. Acoust. Soc.

Am. 84 (4),1145 –1180 (1988).




Experimental setup

Engine 1

Engine 2

52% of total length




Measuring devices

• Thermocouples – To measure the

oscillation temperatureto calculate theoscillation temperatureratio

• Pressure sensors – To calculate the

pressure and velocityamplitude, phase, and

work by using 2 sensormethod

• Data logger




Components of TA engine

Heaters


Pressure

sensor

Resonance

tube

x



Multiple stage performance

• For = 1.93

– The amplification factor for

1-stage engine is 1.76.

– It is 5.10 for 3-stageengine.

• For an amplification of5.10 by 1-stage engine,

the needs to be 5.00.




Continued…




Amplification of acoustic work in

Thermoacoustic engine

Assuming the ideal sterling engine

If = 2 for 1-stage

Then for 2-stage engine =

Pipe




Resonance




Conditions for Resonance

• The engine needs to be sealed carefully to ensure no

leakage.

• If the voltage for the heater is kept constant at 120Vthen it take about 2.4 hours to get resonancecondition.

• The stack used in this experiment has a structure of9/300 mil/cpi

2.

• The water flow rate should be enough to cool theregenerator.

• To oscillate both engines at the same time, thetemperature of the heaters should be kept the same.




Results from the past experiment




Conclusion • The first and most important step in this

research is to get resonance.

• The second most important task is to lowerthe onset temperature.

• If the joints are sealed well and the designconditions are fulfilled then the system canoscillate easily.

• The acoustic work and efficiency can befound after we get resonance.




Future planDuring this year we got some basic knowledge

regarding thermoacoustics and its applications. Nowit’s the time to go forward for some practicalexperiments.

• To perform experiments on loop-shaped engine

and optimize its output power and efficiency by: – Using different types of stakes

– Insulating the heater area

– Changing the length of the engine and position or

number of stakes• After that, to make a double loop configuration and

comparison of both types with respect to efficiencyand other parameters.


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TA Engine Mid term Presentation By Subhan