Air temperature and velocity measurements are important parameters in many applications. A transmitter module is powered by a dc tachogenerator scavenging energy from the airflow has been designed. It transmits the measured air temperature and velocity to a receiving unit. The system consists of a self-powered wireless sensor and the receiver unit. The self-powered sensor has a section for ener...

this paper discusses the results of the full-scale field measurement study to investigate the most efficient application strategy of the hybrid turbine ventilator (htv) in improving the indoor thermal comfort in hot-humid tropics. the effects of three different htv application strategies performance on improving the levels of indoor air temperature, relative humidity (rh) and air velocity were ...

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 ...

A computational fluid dynamics (CFD) model of the air flow generated by an air-assisted sprayer equipped with two axial fans was developed and validated by practical experiments in the laboratory. The CFD model was developed by considering the total air flow supplied by the sprayer fan to be the main parameter, rather than the outlet air velocity. The model was developed for three air flows cor...

Sudden pipe expansions have been known as efficient hydraulic energy dissipaters for a long time. The complex phenomenon of flow separation and velocity discontinuity at the interface of incoming jet and the recirculation flow, results in intensive shear and tensile rupture of the fluid and the associated destructive phenomenon of cavitation. This paper focuses on aeration in sudden pipe expans...

A novel and quite simple method to establish a traceability link between air velocity and the national standards of mass and time is presented in this paper. The method is based on the humidification of flowing air before the blower of a wind tunnel with a known mass flow of water. Then air velocity can be calculated as a function of humidification water flow. The method is compared against a P...

We study drop impact on a deep pool of the same fluid, with an emphasis on the air layer trapped under the droplets from its formation to its rupture. The penetration velocity of the air layer at a very short time scale prior to its rupture is shown, using an energy argument and experimental verification, to be one-half of the impact velocity. We then deduce the dependence of the rupture positi...

A t the impact of a plunging liquid jet with a receiving pool, air bubbles may be entrained if the impact velocity exceeds a critical velocity. New experiments were performed in a two-dimensional plunging jet. The ̄ ow conditions near the inception of air entrainment were investigated. Two mechanisms of air entrainment were visualized at low jet velocities: by elongated air cavity and by foam bu...