Article

Rojo Kurian Daniels, Mar Athanasius College of Engineering , Kothamangalam, Kerala Pin: 686666; Nikhil Babu P ,Mar Athanasius College of Engineering; Bobin Jacob ,Mar Athanasius College of Engineering; Jeoju M Issac ,Mar Athanasius College of Engineering; Ernest Markose Mathew ,Mar Athanasius College of Engineering

The accuracy in measurement of flow rate of liquids and gases is an essential requirement for maintaining the quality of industrial processes and the industrial control loops are used to control the rate of flow of incoming liquids or gases so as to achieve the control objective. Different types of flow measuring techniques are being used in various industries. The common types of flowmeters used in industrial applications are : (a) Obstruction type (differential pressure or variable area) (b) Inferential (turbine type), (c) Electromagnetic, (d) Positive displacement (integrating), (e) fluid dynamic (vortex shedding), (f) Anemometer, (g) ultrasonic and (h) Mass flowmeter (Coriolis). Pressure probe is one of the common instruments used to measure the stagnation pressure, the static pressure, and the flow angle within a fluid stream. When we are designing a pneumatic probe for flow measurements, the effects of blockage, frequency response, pressure hole size and geometry, the local Mach and Reynolds numbers and the relative scale of the phenomena under study must be addressed. Five-hole probes are a newer type after the development of two-hole Conrad and three-hole Cobra probes which are used to measure the pitch and yaw angles of the flow, the stagnation pressure and dynamic or static pressure. Here, five hole probe is fabricated and then calibrated by using continuous wind tunnel. It can be extensively used for three dimensional flow measurements. It is a good alternative to costly techniques of flow measurement.be volumetric or mass flow rate, the medium could be gas or liquid, the measurement could be intrusive or non intrusive, and so on. Hence, different types of flow measuring techniques are being used in various industries. The common types of flowmeters used in industrial applications are : (a) Obstruction type (differential pressure or variable area) (b) Inferential (turbine type), (c) Electromagnetic, (d) Positive displacement (integrating), (e) fluid dynamic (vortex shedding), (f) Anemometer, (g) ultrasonic and (h) Mass flow meter (Coriolis). Pressure probe is one of the common instruments used to measure the stagnation pressure, the static pressure, and the flow angle within a fluid stream. When we are designing a pneumatic probe for flow measurements, the effects of blockage, frequency response, pressure hole size and geometry, the local Mach and Reynolds numbers and the relative scale of the phenomena under study must be addressed. In general, better accuracy is obtainable if smaller probes and transducers are used though this usually means that the response times are longer and that there are greater problems with contamination in dirty environments. Five-hole probes are a newer type after the development of two-hole Conrad and three-hole Cobra probes. They are used to measure the pitch and yaw angles of the flow, the stagnation pressure and dynamic or static pressure. As a result, they provide sufficient information to fully specify the velocity components and pressure fields providing that the stagnation temperature and so, the density, is known. Here, five hole probe is fabricated and then calibrated by using continuous wind tunnel. The probe is faced with known flow velocity for calibration. The velocity of the air stream is kept at 35 m/sec and it is calibrated for different yaw and pitch angle. The graphs for the calibration are compared. From these graphs, it had been found that suitable range for yaw and pitch angle is - 30º and +30º. It can be extensively used for three dimensional flow measurements. It is a good alternative to costly techniques of flow measurement.