scholarly journals The Effect of New Designed Micro Animal Housing on the Air Speed Distribution in the Barn for Providing of Climatic Comfort to the Cattles

2010 ◽  
Vol 9 (1) ◽  
pp. 169-172 ◽  
Author(s):  
Nuh Ugurlu ◽  
Selda Uzal
2019 ◽  
Vol 282 ◽  
pp. 02007 ◽  
Author(s):  
Valeria Cascione ◽  
Eugenio Cavone ◽  
Daniel Maskell ◽  
Andy Shea ◽  
Pete Walker

Hygoscopic finishing materials improve the indoor hygrothermal comfort and air quality, as they reduce the extremes of variation in relative humidity. This property, known as moisture buffering, is related to the capacity of hygroscopic materials to adsorb and desorb moisture from the air. Air velocity plays an important role on the sorption performances of materials: increasing the air speed leads to increased moisture buffering capacity. In order to obtain comparable results, several moisture buffering protocols require the air speed to be constant and around 0.1 m/s during tests. However, those tests are usually performed in climatic chambers, where air speed cannot be controlled and the flow may not be homogenous. The aim of this study is to demonstrate, that positioning test specimens in different locations within the same chamber gives different moisture buffering value results, due to the non-homogenous air speed distribution. For this reason, air velocity has been monitored, measuring the differential pressure and air speed in different locations in a climatic chamber. Moisture buffering tests have been performed in six locations of the chamber and a correlation between the two analyses has been evaluated. The significance of this paper is to understand the relationship between air speed and moisture buffering performances, in order to determine an air velocity correction factor, which enables the moisture buffering value to be evaluated when existing protocols cannot be adhered.


2021 ◽  
pp. 107979
Author(s):  
Maohui Luo ◽  
Hui Zhang ◽  
Paul Raftery ◽  
Linxuan Zhou ◽  
Thomas Parkinson ◽  
...  

2018 ◽  
Vol 61 (2) ◽  
pp. 449-460 ◽  
Author(s):  
Jessica L. Drewry ◽  
Mario R. Mondaca ◽  
Brian D. Luck ◽  
Christopher Y. Choi

Abstract.The design and operation of ventilation systems for animal housing is a crucial component in maintaining a suitable environment for both animals and workers by removing heat, moisture, and gas species. However, important design and operational criteria, such as profiles of velocity and extent of mixing within animal housing, can be difficult to study experimentally. Thus, a computational fluid dynamics (CFD) model of a commercial dairy holding area, including the generation of transport of heat and gas species within the domain, was developed. The animal-occupied zone (AOZ) was modeled using porous media. The model was evaluated with experimental data of velocity and gas concentration. Results indicated that the airflow uniformity and air speed could be increased within the holding area by modifying the configuration of the side curtain openings and using concrete walls to guide airflow; a 20% increase in average velocity within the AOZ was achieved. Results of the CFD model have shown it to be an effective tool for gaining insight into the complex mixing patterns within holding areas to improve the design of animal housing. Keywords: Animal-occupied zone, Computational fluid dynamics, Greenhouse gas emissions, Holding area.


2012 ◽  
Vol 9 (1) ◽  
Author(s):  
Sulistyo Atmadi ◽  
Ahmad Jamaludin Fitroh

 One technique to improve the power output of a wind turbine is by implementing a diffuser, which is called the diffuser augmented wind turbine (DAWT). The area ratio between the inlet and outlet of the diffuser increases the flow rate inside the diffuser which in effect produces higher output power. In this research, a 2 meters rotor diameter was used. Diffuser diameter ratio variation of 2, 3, 4, and 5 were chosen which provides inlet diameter of 4, 6, 8, and 10 meter respectively. Power rotor coefficient is assumed to be constant of 0.30. Air speed distribution inside the diffuser is calculated using CFD method. The inlet speed to the diffuser is varied to give 4 different speeds. The wind angle at the inlet is also varied at 0º, 30º and 60º. The simulation result showed that at 0 degree angle, diffuser diameter ratio variation of 2, 3, 4, and 5 will increase the power output about 58, 622, 3169, and 11519 times respectively. It also showed that the increase in the output power for diameter diffuser ratio of 2 at 0º and 60º angle is 58 and 4 times respectively. Keywords:Wind turbine, Diffuser, CFD


2019 ◽  
Vol 2 (5) ◽  
Author(s):  
Ji-hua Hu ◽  
Jia-xian Liang

Interstation travel speed is an important indicator of the running state of hybrid Bus Rapid Transit and passenger experience. Due to the influence of road traffic, traffic lights and other factors, the interstation travel speeds are often some kind of multi-peak and it is difficult to use a single distribution to model them. In this paper, a Gaussian mixture model charactizing the interstation travel speed of hybrid BRT under a Bayesian framework is established. The parameters of the model are inferred using the Reversible-Jump Markov Chain Monte Carlo approach (RJMCMC), including the number of model components and the weight, mean and variance of each component. Then the model is applied to Guangzhou BRT, a kind of hybrid BRT. From the results, it can be observed that the model can very effectively describe the heterogeneous speed data among different inter-stations, and provide richer information usually not available from the traditional models, and the model also produces an excellent fit to each multimodal speed distribution curve of the inter-stations. The causes of different speed distribution can be identified through investigating the Internet map of GBRT, they are big road traffic and long traffic lights respectively, which always contribute to a main road crossing. So, the BRT lane should be elevated through the main road to decrease the complexity of the running state.


2013 ◽  
Vol 12 (3) ◽  
pp. 493-501 ◽  
Author(s):  
Gerardo Iannone ◽  
Claudio Guarnaccia ◽  
Joseph Quartieri

Micromachines ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 366
Author(s):  
Yang Xia ◽  
Yun Tian ◽  
Lanbin Zhang ◽  
Zhihao Ma ◽  
Huliang Dai ◽  
...  

We present an optimized flutter-driven triboelectric nanogenerator (TENG) for wind energy harvesting. The vibration and power generation characteristics of this TENG are investigated in detail, and a low cut-in wind speed of 3.4 m/s is achieved. It is found that the air speed, the thickness and length of the membrane, and the distance between the electrode plates mainly determine the PTFE membrane’s vibration behavior and the performance of TENG. With the optimized value of the thickness and length of the membrane and the distance of the electrode plates, the peak open-circuit voltage and output power of TENG reach 297 V and 0.46 mW at a wind speed of 10 m/s. The energy generated by TENG can directly light up dozens of LEDs and keep a digital watch running continuously by charging a capacitor of 100 μF at a wind speed of 8 m/s.


Sign in / Sign up

Export Citation Format

Share Document