A Networked Two-Dimensional Sonic Anemometer System for the Measurement of Air Velocity in Greenhouses
نویسندگان
چکیده
The experimental study of air movement induced by natural ventilation in greenhouses requires a system to measure the air velocity "eld. A networked, two-dimensional sonic anemometer system was developed for simultaneous measurement of the instantaneous air speed and direction at 12 locations. The system performance was tested and validated against a mass #ow controller and a commercial, three-dimensional, ultrasonic anemometer. The sonic anemometer system was then tested in greenhouse conditions. It showed that the high resolution, stability, proper frequency response and low cost of the system were well adapted for the study of the air velocity "eld in greenhouses. ( 1999 Silsoe Research Institute
منابع مشابه
A Comprehensive Study on a Latent Heat Thermal Energy Storage System and its Feasible Applications in Greenhouses
Abstract Energy crisis is a major challenge in the current world. Latent heat thermal energy storage (LHTES) systems are known as equipment with promising performance by which thermal energy can be recovered. In the present study a comprehensive theoretical and experimental investigation is performed on a LHTES system containing PEG1000 as phase change material (PCM). Discussed topics can be ca...
متن کاملAnalysis of the Air Flow Generated by an Air-Assisted Sprayer Equipped with Two Axial Fans Using a 3D Sonic Anemometer
The flow of air generated by a new design of air assisted sprayer equipped with two axial fans of reversed rotation was analyzed. For this goal, a 3D sonic anemometer has been used (accuracy: 1.5%; measurement range: 0 to 45 m/s). The study was divided into a static test and a dynamic test. During the static test, the air velocity in the working vicinity of the sprayer was measured considering ...
متن کاملHow Well Can We Measure the Vertical Wind Speed? Implications for Fluxes of Energy and Mass
Sonic anemometers are capable of measuring the wind speed in all three dimensions at high frequencies (10–50 Hz), and are relied upon to estimate eddy-covariance-based fluxes of mass and energy over a wide variety of surfaces and ecosystems. In this study, wind-velocity measurement errors from a three-dimensional sonic anemometer with a nonorthogonal transducer orientation were estimated for ov...
متن کاملEffects of obstructions, sample size and sample rate on ultrasonic anemometer measurements underground
In fluctuating airflow, continuous air velocity recording is the most reliable method of air velocity measurement. It allows for fast recognition of changes and the calculation of long-term averages. Also, it enables the mine operator to identify when the airflow has decreased to a point requiring action. Using ultrasonic anemometers provides an accurate option for continuous air velocity monit...
متن کاملThermography and Sonic Anemometry to Analyze Air Heaters in Mediterranean Greenhouses
The present work has developed a methodology based on thermography and sonic anemometry for studying the microclimate in Mediterranean greenhouses equipped with air heaters and polyethylene distribution ducts to distribute the warm air. Sonic anemometry allows us to identify the airflow pattern generated by the heaters and to analyze the temperature distribution inside the greenhouse, while the...
متن کامل