Unit III Wind Tunnel Measurements

Pressure Measurements

Introduction

• Pressure measurement is important in many fluid mechanics related applications. 
• From appropriate pressure measurements velocity, aerodynamic forces and moments can be determined. 
• Pressure is measured by the force acting on unit area. Measuring devices usually indicate differential pressure i.e. in relation with atmospheric pressure.This is called gauge pressure. 
• The measured pressure may be positive or negative with reference to the atmospheric pressure .
• A negative gauge pressure is referred to as vacuum.