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A computational analysis in a rotary regenerative air preheater subject to pre-established mass flow rate is performed. The heat transfer rate, the pressure drop and the outlet temperatures of gas streams are calculated from different matrix porosity values. The fluid flow and the convective heat transfer coefficient are determined from correlations. The total heat transfer is obtained using the Effectiveness-NTU method specific to regenerative air preheaters. Three typical regenerative air preheaters with both streams under the laminar flow regime are investigated. A range of porosity values that provide good thermal exchange and low pressure drop in the equipment is chosen for each examined air preheater. The behavior of the outlet temperatures of each gas stream as function of porosity is also analyzed. The results show that the porosity ranges shorten when the typical pressured drop values for each regenerative air preheater are introduced in the analysis. In addition, the behavior of the outlet temperatures is compatible with the behavior of the heat transfer rate as the porosity changes.

In all studies involving wind speed, such as meteorology, wind turbines and agriculture accurate speed information for decision making is required. There are several types of anemometers, with medium and high costs, such as cup, hot wire and pitot tubes, the hot wire being more sensitive and expensive than others. The device developed in this work is the cup anemometer, that is easy to build. The great advantage of this device is the low cost, with an approximate value of US$ 50.00, using simple materials that are easy to find in commercial stores. The Reed Switch sensor is also another advantage as it does not require a sophisticated programming, as well as the open platform Arduino. The use of theoretical aerodynamic drag coefficients and the presented calculations resulted in values very close to a commercial anemometer. The coefficient of determination between the cup Anemometer and the standard sensor of Meteorological Research Institute IPMet/Brazil is R 2 =0.9999, indicating strong correlation between the instruments. As the reference anemometer (IPMet) has high embedded technology and the prototype is low cost, we conclude that the project has an attractive cost benefit for possible development and production, reaching the objective of this work.

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