Cooling Techniques II-Physics-Project Presentation, Slides of Physics

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Presentation Layout

 Introduction  Film Cooling  Types of Film Cooling  Aims and objectives  Turbulence Intensity  Experimental Test Facility  Measurement Techniques  Experiment Procedure  Experiments  Summary and Conclusion  Future Recommendation

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Introduction

 The gas turbine industry continues to push aircraft engine performance to higher levels.  Engine designs are yielding higher efficiencies and thrust-to-weight ratios for modern aircraft.  Increased performance is the increase of turbine inlet temperatures.  Higher turbine inlet temperatures yield higher thermodynamic efficiencies.  There are many different cooling techniques that have been devised.

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Cooling Techniques

 Internal convection channels  Single-crystal fabrication  Thermal barrier coatings  Film Cooling

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Film Cooling

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Types of Film Cooling

Film Cooling

Stream-wise Injection Lateral Injection

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Aims and objectives

 To develop an experimental setup for testing  To develop a ‘standard’ turbulence intensity based on the design concepts  To vary turbulence intensity to check the variations in thermal performance  To measure the thermal performance  To compare the different results  To compare Effectiveness from different Turbulence Intensities

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Turbulence Intensity

 The turbulence intensity, also often referred to as turbulence level, is defined as:

Where S.D is the root-mean-square of the velocity fluctuations and is the mean velocity

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Experimental Test Facility

Corrugations

Air Duct Test Section

HOT Airsupply

Heating Box

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Re-Modeling of Test Facility

The original duct was replaced with newly compact design duct to achieve the required velocity

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Measurement Techniques

 There are no of film cooling measurement techniques some are given below:

 Pressure Sensitive paints  Liquid Crystal Thermo-graphy  Thermocouples  Infrared Thermo-graphy

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Measurements

 Thermocouple technique was used to evaluate

thermal variations

 Reasons for selecting this are

_1. Its availability

2. Simplicity in measurements
3. Wide temperature range_

 Problem with this method is that it gives data at

limited number of points

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Measurements

Velocity Measurements Hotwire Thermo Anemometer  Velocity range 0 m/s to 20 m/s  Temperature range -20^0 C to 70^0 C  Response time 1 milli sec  Probe diameter 6 mm  Extendable length of 5 feet

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Measurements

Measurement of Turbulence Intensity:

Length of Grid

width

Velocity measurement in front of Turbulence Grid

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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

Velocity (Y

- Axis

)

Z-Axis

Velocity Variation