Browsing by Author "Schmidt, David"
Now showing 1 - 13 of 13
- Results Per Page
- Sort Options
Item Biofilter design information(2020) Schmidt, David; Jacobson, Larry; Nicolai, DavidOdor emissions from livestock and poultry facilities are a source of contention in many areas of Minnesota and across the United States. Under certain conditions odor emissions have been known to affect neighbors and communities at distances of a mile or more from the odor source. One odor control technology that has been shown to be both economical and effective is a biofilter. Biofiltration can reduce odor and hydrogen sulfide emissions from livestock and poultry facilities by as much as 95% and ammonia by 65%. This method of odor control has been used in industry for many years and was recently adapted for use in livestock and poultry systems. Biofilters are most easily adapted to mechanically ventilated buildings or on the pit fans of naturally ventilated buildings. Biofilters can also treat air vented from covered manure storage covers.Item COWS PRODUCE MORE THAN MILK!(1997-05-21) Schmidt, DavidItem Flight-Dynamics, Flutter, and Active-Flutter-Suppression Analyses of a Flexible Flying-Wing Research Drone(As presented at the NASA Armstrong Flight Research Center Edwards AFB, CA, 2015-06-15) Schmidt, DavidItem Flight-Dynamics, Flutter, and Active-Flutter-Suppression Analysis of a Flexible Flying-Wing Research Drone(Aerospace Flutter and Dynamics Council (AFDC) Meeting, Spring 2015, 2015-04-16) Schmidt, DavidItem Foaming in Swine Manure Pits: Current Understanding and Solutions(University of Minnesota. Minnesota Extension Service, 2012-09) Clanton, Chuck; Jacobson, Larry; Hu, Bo; Akdeniz, Neslihan; Schmidt, DavidItem MATLAB-Based Flight-Dynamics and Flutter Modeling of a Flexible Flying-Wing Research Drone(2015-05-19) Schmidt, DavidA relatively low-order, linear dynamic model is developed for the longitudinal flight- dynamics analysis of a flexible, flying-wing research drone, and results are compared to previously published results. The model includes the dynamics of both the rigid-body and elastic degrees of freedom, and the subject vehicle is designed to flutter within its flight envelope. The vehicle of interest is a 12-pound unmanned, flying-wing aircraft with a wingspan of 10 ft. In the modeling, the rigid-body degrees of freedom (DOFs) are defined in terms of motion of a vehicle- fixed coordinate frame, as required for flight-dynamics analysis. As a result, the state variables corresponding to the rigid-body DOFs are identical to those used in modeling a rigid vehicle, and the additional states are associated with the elastic degrees of freedom. Both body-freedom and bending-torsion flutter conditions are indicated by the model, and it is shown that the flutter speeds, frequencies, and genesis modes suggested by this low-order model agree very well with the analytical predictions and flight-test results reported in the literature. The longitudinal dynamics of the vehicle are characterized by a slightly unstable Phugoid mode, a well-damped, pitch-dominated, elastic-short-period mode, and the stable or unstable aeroelastic modes. A classical, rigid-body, short-period mode does not exist.Item New technologies in manure management(2001-09-15) Schmidt, David; Bicudo, JoseItem Odor and H2S Emissions from Dairy Facilities(1999-05-25) Schmidt, DavidItem Oral history interview with David Schmidt(Charles Babbage Institute, 2012-04-05) Schmidt, DavidCo-founder of Tymshare, David Schmidt, reflects on his early career, the founding of Tymshare, and the firm’s technology, key personnel, competitive environment, and early growth before leaving to found Mascor.Item Preparing an Odor Management Plan(St. Paul, MN: University of Minnesota Extension Service, 2001) Schmidt, David; Jacobson, Larry; Janni, KevinItem Roll Press Compaction of Corn Stover and Perennial Grasses(2011-11) Kaliyan, Nalladurai; Morey, Vance; Schmidt, David; Tiffany, DouglasIncreasing the bulk density of biomass materials to at least 240 kg/m3 (15 lb/ft3) is important for efficient handling and truck transport from the field to an end user. Roll press compaction increased the bulk density of coarsely ground biomass materials to 265 to 365 kg/m3 (16 to 23 lb/ft3).Item Stability Augmentation and Active Flutter Suppression of a Flexible Flying-Wing Drone(2015-05-19) Schmidt, DavidIntegrated control laws are developed for stability augmentation and active flutter suppression (AFS) of a flexible, flying-wing drone. The vehicle is a 12-pound unmanned, flying- wing research aircraft with a 10 ft wingspan. AFS is flight critical since the subject vehicle is designed to flutter within its flight envelope. The critical flutter condition involves aeroelastic interactions between the rigid-body and elastic degrees of freedom; hence the control laws must simultaneously address both rigid-body stability augmentation and flutter suppression. The control-synthesis approach is motivated by the concept of Identically Located Force and Acceleration (ILAF), successfully applied on some previous operational aircraft. Based on the flutter characteristics and on conventional stability-augmentation concepts, two simple loop closures are suggested. It is shown that this control architecture robustly stabilizes the body- freedom-flutter condition, increases the damping of the second aeroelastic mode (which becomes a second flutter mode at higher velocity), and provides reasonably conventional vehicle pitch- attitude response. The critical factors limiting the performance of the feedback system are identified to be the bandwidth of the surface actuators and the pitch effectiveness of the control surfaces.Item Survey of Existing Aeroservoelastic Models(2015-05-04) Danowsky, Brian; Schmidt, DavidThis working paper documents a survey of existing mathematical models of aeroservoelastic aircraft. For the purposes of this working paper, the primary purpose of such models is for control analysis and design. Enhanced validation and simulation (piloted and non-piloted) are also important.