Mechanical Engineering Commons^™

Changing Climates And Extreme Weather For Minnesota, Patrick A. Tebbe

Mechanical and Civil Engineering Department Publications

Climate change is impacting the design, prediction, and operation of HVAC systems for the built environment, and will continue to do so for the foreseeable future. This presentation reviews climate predictions for the upper Midwest and how they will affect the HVAC industry. Topics such as changing design conditions, extreme weather impact, and increased electrification will be addressed.

Improving Vertical Axis Wind Turbine (Vawt) Performance With Placement Strategies: Final Report, Patrick A. Tebbe, Nazli A. Yilmaz Wodzinski, Namyong Lee

Mechanical and Civil Engineering Department Publications

This project was focused on the use and placement of vertical axis wind turbines (VAWTs). Studies were focused on areas not typically addressed in previous work; small wind at very low elevations (i.e. within the boundary layer). Numerical studies were made of how VAWTs function as well as the potential wind environments they may be placed in. A simplified numerical code, based on two-dimensional potential flow functions, was developed to model flow around buildings and other structures. The code allows a rapid determination of regions where flow may experience speed-up and where turbulence may result.

Experimental facilities were designed and …

Flow Fields Past Grain Bins As It Relates To Vertical Axis Wind Turbine Placement Optimization, Jon Richter

All Graduate Theses, Dissertations, and Other Capstone Projects

This thesis studies the 3D flow field of grain bins as it relates to Vertical Axis Wind Turbine (VAWT) placement. Numerical CFD simulations using ANSYS FLUENT were created and validated with the Minnesota State University, Mankato water channel. It was found that the best speed-up regions were on the outer most sides of the models, closest to the walls of the water channel. The model that is furthest upwind in the group has the best speed-up velocity. As the models become closer together, an asymmetric flow field develops. VAWT placement between the models for any case researched is not recommended. …

Performance Analysis Of Solar Walls In Minnesota: Final Project Report, Patrick A. Tebbe, Saeed Moaveni, Louis Schwartzkopf

Mechanical and Civil Engineering Department Publications

A study of unglazed transpired solar collectors (referred to as solar walls for this report), has been undertaken. Several installations in the Twin Cities, MN region have been identified, researched, and studied. A combination of weather stations, data logging systems, and building energy management systems were used to collect experimental data on four buildings. Performance calculations were then performed for these buildings and compared with various performance/modeling tools.

Investigation Into The Potential Use Of Windbreaks To Improve Solar Collector Performance, Michael Watts

All Graduate Theses, Dissertations, and Other Capstone Projects

The global demand for energy is ever increasing; however, the world has a limited number of fossil fuels available. Therefore, alternative renewable energy sources must be utilized. For this reason, solar thermal collectors have become an increasingly popular method for providing hot water or space heating. However, solar thermal collectors are most commonly used in areas that experience warm climates throughout the year. In areas that experience seasonal climates, the cold temperatures and harsh climate conditions significantly reduce the performance of solar thermal collectors during the winter months. This thesis examined the potential that the implementation of a windbreak could …

A Mathematical Model And Simulation Of Natural Circulation Loop Thermalhydraulics, Nihad E. Daidzic

Aviation Department Publications

In this work, a simple, nonlinear, seventh-order mathematical model with lumped parameter analysis of the thermalhydraulic processes in a natural circulation steam boiler loop is presented. Digital simulation has been performed in order to predict open loop transients in severe accidental situations. Parts of the circulation loop such as the steam drum, downcomer, and riser were modelled separately on the basis of the integral balance equations. The two-phase flow in the steam drum and in the riser was modelled with the aid of a homogeneous-equilibrium, two-phase flow model. Special care was taken to ensure the stability of the numerical scheme, …