Project Proposal Defense Final

Project Proposal Defense Project Title:

Design of Wind Tunnel By Anuj Shrestha (060bme604) Manish Rijal (060bme614) Santosh Sharma (060bme632)

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contents

What is a wind tunnel? How it works? Types of wind tunnel. Aerodynamics. Uses of wind tunnel. What studies can be carried out? Objectives of project. Expected outcome. Technical specification. Methodology. Action plan on weekly basis (Gantt chart). Final task. Budgeting. Conclusion.

What is a wind tunnel? • A wind tunnel is a research tool developed to assist with studying the effects of air moving over or around solid objects. • It may also be called as a facility, by artificially producing airflow relative to a stationary body that measures aerodynamic force and pressure distribution to simulate with actual conditions. • Wind-tunnels represent a useful tool for investigating various flow phenomena.

How it works?

• A wind tunnel is specially designed to suck or blow air. • The design is made such that a high velocity is developed at a section where test is done called as test section. • The test material is generally a replica of the object to be studied, is kept in the test section and different readings are taken to perform different research works. • Accessories for the study of flow: Threads, Pitot tube Probes, Dye or smoke

Types of wind tunnel Based on architecture open circuit tunnels • No guided return of air.

closed circuit tunnels • Guided return of air.

Based on wind speed Subsonic M: 0.0-0.7

Supersonic M: 1.2-5

Transonic M: 0.7-1.2

Hypersonic M: >5 M=Mach number

Aerodynamics

• Aerospace engineering • It is a significant factor in any type of vehicle design, including automobiles. • Prediction of forces and moments in sailing. • Structural engineers use aerodynamics, and particularly aero-elasticity, to calculate wind loads in the design of large buildings and bridges. • Urban aerodynamics seeks to help town planners and designers improve comfort in outdoor spaces, create urban microclimates and reduce the effects of urban pollution. • The field of environmental aerodynamics studies the ways atmospheric circulation and flight mechanics affects ecosystems. • The aerodynamics of internal passages is important in heating/ventilation, gas piping, and in automotive engines where detailed flow patterns strongly affect the performance of the engine. And all aerodynamic tests is performed in a wind tunnel.

Uses of wind tunnel • Measure aerodynamic property(ies). • Simulate with actual conditions. • Lets safely take measurements which are impossible to make at the actual condition. • Test can be performed under controlled conditions, which were difficult with traditional winds or whirling arm. • Long duration of tests which were impossible by any other equipments.

What studies can be carried out? • Drag/Lift measurements on aircraft, helicopters, missiles, racing cars. • Drag/Lift/Moment characteristics of airfoils and wings. • Static stability of aircraft and missiles • Dynamic stability derivatives of aircraft • Surface Pressure distributions on nearly all systems. • Flow visualizations (with smoke, oil, talcum). • Propeller performances (torque, thrust, power, efficiency, etc.). • Performances of air-breathing engines. • Wind effects on buildings, towers, bridges, automobiles. • Heat transfer properties of engines and aircraft.

Objectives of the project • To form a basis for complete design of a wind tunnel. • Understanding the basic of aerodynamics. • Studying the characteristics of flow in the tunnel. • The completion of project would accelerate the interests of individual and institutions in the field of aerodynamics.

Expected outcomes • Design and calculations • This will strengthen the interest of students towards the field. • This would open a new field in design of airfoils in the country itself. • After the completion of project interested institution or individual can built their own wind tunnel with the locally available materials. • This project will prove itself as a milestone in the field of aerodynamics research in Nepal.

Technical Specification • Rough estimation of the size we are trying to design is in

shown in the orthographic

view below. •Size is effected by space limitations, what we are going to test and cost. Parts: Settling chamber, compressor, test section, diffuser and drive section.

All dimensions are in inch

methodology • Literature review. (searching books, manuals and visiting experts.) • Studying of axial fan. (about the velocity it can generate and power required)

• Initial design (design calculations and detailed drawings of components) • Building a wind tunnel model (scale- 1:3) (fabrication based on initial design)

• Model wind tunnel study (viewing the flow using threads, smoke) • Optimization of Design (changes in design based on model study) • Final Design (detailed design with suggestion of materials for the building prototype)

Action plan in weekly basis Gantt chart Chaitra 2063

Baisakh 2064

Jestha 2064

Asar 2064

Shravan 2064

Bhadra 2064

Ashwin 2064

Kartik 2064

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Literature review study about axial fan initial design work

building a proto-type wind tunnel

testing the wind tunnel optimization of Design

final design

The action plan may have certain changes in accordance to our academic calendar.

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Final task • • • •

Study of wind tunnel Design and Calculation Material selection for prototype design. Complete design and suggestion for fabricating prototype. • Preparation of report and final presentation.

Budgeting • Nrs 11000/- for simple wind tunnel model fabrication. • Nrs 2000/- for stationary items. • Nrs 2000/- for miscellaneous. Total: Nrs 15000/-

conclusion • An old concept but it is still an effective tool for almost all aerodynamic tests and researches. • Design will open the doors for farther aerodynamic research in Nepal. • A complete design and building a model just meets the criterion of our final year project.

A meaningful project.

Questions