JAWAHARLAL NEHRU TECHNOLOGICAL UNIVERSITY HYDERABAD

Pre-Requisites

Aerodynamics

Course Objectives:

• To provide details, operating principles and limitations of forces, pressure, velocity and temperature measurements. To describe flow visualization techniques and to highlight in depth discussion of Analog methods.

Course Outcomes:

• Knowledge on measurement techniques in aerodynamic flow.
• Acquiring basics of wind tunnel measurement systems
• Specific instruments for flow parameter measurement like pressure, velocity, temperature etc.

UNIT - I

Basic Measurements in Fluid Mechanics: Objective of experimental studies – Fluid mechanics measurements – Properties of fluids – Measuring instruments – Performance terms associated with measurement systems – Direct measurements - Analogue methods – Flow visualization –Components of measuring systems – Importance of model studies.

UNIT - II

Characteristics of Measurements: Characteristic features, operation and performance of low speed, transonic, supersonic and special tunnels - Power losses in a wind tunnel – Instrumentation of wind tunnels – Turbulence- Wind tunnel balance –principles, types and classifications -Balance calibration.

UNIT - III

Flow Visualization and Analogue Methods: Principles of Flow Visualization – Hele-Shaw apparatus - Interferometer – Fringe-Displacement method – Schlieren system – Shadowgraph - Hydraulic analogy – Hydraulic jumps – Electrolytic tank

UNIT - IV

Pressure, Velocity and Temperature Measurements: Measurement of static and total pressures in low and high-speed flows- Pitot-Static tube characteristics - Pressure transducers – principle and operation – Velocity measurements - Hot-wire anemometry – LDV – PIV: Temperature measurements.

UNIT - V

Special Flows and Uncertainty Analysis: Experiments on Taylor-Proudman theorem and Ekman layer – Measurements in boundary layers - Data acquisition and processing – Signal conditioning - Uncertainty analysis – Estimation of measurement errors – External estimate of the error – Internal estimate of the error – Uncertainty calculation - Uses of uncertainty analysis.

TEXT BOOKS:

• 1. Rathakrishnan, E., “Instrumentation, Measurements, and Experiments in Fluids,” CRC Press –Taylor & Francis, 2007.
• 2. Robert B Northrop, “Introduction to Instrumentation and Measurements”, Second Edition, CRC Press, Taylor & Francis, 2006.

REFERENCE BOOKS:

• 1. Pope, A., and Goin, L., "High Speed Wind Tunnel Testing", John Wiley, 1985.Bradsaw Experimental Fluid Mechanics.
• 2. NAL-UNI Lecture Series 12: Experimental Aerodynamics, NAL SP 98 01 April 1998
• 3. Lecture course on "Advanced Flow diagnostic techniques" 17-19 September 2008 NAL, Bangalore