No description available.

No description available.

An analytical procedure to determine the effectiveness of greenhouse, as solar collectors was presented. This procedure was used to predict the effect of several construction parameters on solar radiation input to greenhouses. The orientation of the greenhouse was found to be the most effective construction parameter controlling solar radiation input to greenhouses. The effective albedo of the plant canopy was also found to be a significant factor. A new solar greenhouse design, suitable for high latitude regions was developed. The results showed that an internal solar collector could be incorporated as an integral part of the greenhouse design. The concept developed could be used as a free-standing greenhouse or in a combination with livestock building. The efficiency of the solar input was investigated for the conventional and the shed greenhouses, both as a free-standing unit and a greenhouse-animal shelter system, using computed simulation analyses. The results indicated that the efficiency of solar input is highly dependent on location; the effect of location on the shed type design is more profound. A typical case of a greenhouse-hog barn production system was investigated using computer simulation analyses. The results showed that such a food production system achieves a significant reduction in conventional fuel consumption due to both animal waste heat recovery and solar energy utilization. / Graduate and Postdoctoral Studies / Graduate

The airflow pattern and contaminant distribution under non-isothermal turbulent flow conditions in a swine growing/finishing building were investigated experimentally and numerically. In the test facility, the ventilation system consisted of discontinuous ceiling inlets with recirculation assisted slots. Air speed, dust and ammonia concentration at selected locations in the-building were measured during the winter ventilation season in a cold climate. The corresponding temperature distribution at one cross section within the air space also was measured. Experimentally it was found that both the ventilation rate and the recirculation rate had a limited effect on the dust concentration. The ventilation rate had a significant effect on the ammonia concentration in the air space, while the recirculation rate did not affect the ammonia concentration. The FLUENT computer code was used to simulate the air flow pattern and ammonia concentration in the swine building. The numerical simulation model used was the k-$\varepsilon$ turbulence model which includes a buoyancy term. The predicted airflow pattern indicated that the flow structure in such a ventilated swine barn is a three-dimensional flow. The three-dimensional flow structure and the contaminant concentration and temperature at the human breathing line were highly affected by the combined behavior of ceiling inlet jets and recirculation slot jets. The presence of pigs in the swine building had three effects: the air stream near the pigs was deflected; the air speed above the pigs was increased; and the ammonia concentration in the air space was decreased. Both experimental and numerical results showed that temperature and ammonia concentration were uniformly distributed across most of the air space in a building ventilated with discontinuous ceiling inlets and recirculation slots. Numerical results also indicated that the heat generated by animals affected the airflow pattern. Increasing the heat load at the floor resulted in increased air speed, temperature, contamination level, turbulence kinetic energy, dissipation rate and effective viscosity along the breathing line. The placement of the ceiling inlet and the recirculation duct affected airflow patterns, but had only a slight effect on the distribution of temperature and ammonia concentration along the human breathing line. Increasing the flow rate of cleaned recirculation airflow resulted in lower ammonia contaminant level along the human breathing line. However, higher flow rates of cleaned recirculation air means there will be higher fan operation and air cleaning costs. The optimum ratio of ventilation rate to the cleaned recirculation air rate appeared to be approximately 1:4.

Diss. (sammanfattning) Skara : Sveriges lantbruksuniv., 2007. / Härtill 4 uppsatser.

Examensarbete.

Thesis (Ph. D.)--University of Missouri-Columbia, 1996. / Typescript. Vita. Includes bibliographical references (leaves 112-119). Also available on the Internet.

Thesis (Ph. D.)--University of Missouri-Columbia, 1996. / Typescript. Vita. Includes bibliographical references (leaves 112-119). Also available on the Internet.

Typescript (photocopy). / Digitized by Kansas Correctional Industries

Climatic conditions inside the dairy barn do not concern dairy farmers until those conditions begin to affect productivity and, consequently, profits. As heat and humidity increase beyond the cow's comfort levels, milk production declines, as does fertility and the welfare of the cow in general. To reinforce the cooling mechanisms currently used, this work proposes an alternative system for reducing the risk of heat stress. This innovative conductive cooling system does not depend on current weather conditions, and it does not require significant modifications when it is installed or during its operation. Also, the system circulates water that can be reused. Given that a review of the literature found very few related studies, it is suggested that each freestall be equipped with a viable prototype in the form of a waterbed able to exchange heat. Such a prototype has been simulated using Computational Fluid Dynamics (CFD) and later verified by a set of experiments designed to confirm its cooling capacity. Furthermore, this investigation sets the foundation for modeling temperature in a water supply system linked to the waterbeds. EPANET, a software program developed by the Environmental Protection Agency, simulates the hydraulic model. Its Water Quality Solver has been modified according to an analogy in the governing equation that compares mass to heat transfer and serves to simulate water temperature as the water is transported from its source to the point of delivery and then as it returns to the same source.