Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 20 of 40 for “"Compression systems"”.
-
Feedback stabilization of compression systems
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 1993.
-
Aerodynamic-rotordynamic interaction in axial compression systems
Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2000.
-
Potentials for COP increase in vapor compression systems
… opportunities for COP increase in vapor compression systems: work recovery ejectors, condenser subcooling and increase of relative size of heat exchangers (HXs). Regarding work recovery ejectors, experimental results showed that the COP of the ejector system increased between 8.2% and …
-
Dynamic modeling, validation, and control for vapor compression systems
… process of model-based control design for vapor compression systems (VCSs), from nonlinear model development to linearization and control formulation. Addressing gaps in the previous literature, the equations behind each model and control approach are clearly stated and emphasis is placed on …
-
Model free real-time optimization for vapor compression systems
A vapor compression system's optimal input settings vary according to changes in environmental conditions. Tracking these optimal input trajectories can be challenging when insufficient information for a reliable system model is available. An alternative set of optimization approaches use system …
-
Extremum seeking control of battery powered vapor compression systems for vehicles
… energy optimization of battery powered vapor compression systems (VCS) for vehicles. Battery powered VCS are critical for maintaining passenger comfort in engine-off situations, and are especially important to long-haul truck drivers who sleep inside their vehicle overnight. However, one …
-
An Improved Streamline Curvature Approach for Off-Design Analysis of Transonic Compression Systems
A streamline curvature (SLC) throughflow numerical model was assessed and modified to better approximate the flow fields of highly transonic fans typical of military fighter applications. Specifically, improvements in total pressure loss modeling were implemented to ensure accurate and reliable …
-
TRANSIENT MODELING OF TWO-STAGE AND VARIABLE REFRIGERANT FLOW VAPOR COMPRESSION SYSTEMS WITH FROSTING AND DEFROSTING
… framework for the transient simulation of vapor compression systems. This framework contains a wide range of components and its modular nature enables an arbitrary cycle configuration to be analyzed. One of the highlights of this framework is the first-principles heat exchanger models with many …
-
Performance optimization of advanced vapor compression systems working with low-GWP refrigerants using numerical and experimental methods
Submission published under a 24 month embargo labeled 'U of I Access', the embargo will last until 2026-05-01
-
Experimental and numerical investigation of the design and control of vapor-compression systems with integration of two-phase ejectors for performance enhancement through expansion work recovery
… to improve the efficiency and capacity of vapor-compression refrigeration cycles by means of expansion work recovery has received significant attention in the past decade. Research has focused primarily on the design and performance of the ejector and the effect the ejector has on cycle …
-
Improving producibility in aerospace engine manufacturing : process automation vs. process reengineering
… operation, including Pratt & Whitney's Compression Systems Module Center, producibility problems can be major drivers of cost. Much of the literature focuses on design for manufacturability as a solution to producibility problems. While this is a valuable approach, this study focuses on …
-
Applications of axial and radial compressor dynamic system modeling
… projects related to axial and centrifugal compression systems. The projects are related by the underlying dynamic system modeling approach that is common in all of them. Two types of models are introduced, suitable for modeling the dynamic behavior of axial and centrifugal compression …
-
Estimating File Compressibility Using File Extensions
Adaptive compression systems dynamically choose a compression strategy — including no compression — by monitoring CPU usage, output rate, expected time to compress, and perhaps most importantly, the estimated compressibility of the data. Many adaptive compression systems were designed with the …
-
Evaluation of different forms of compression in digital hearing aids
… reduced dynamic range of hearing, thus amplitude compression may provide adequate amplification of soft sounds without uncomfortable over-amplification of loud sounds caused by conventional linear amplification. Although compression is conceptually straightforward, there are various design …
-
Cop and capacity improvement through work and heat recovery by using vortex tube
… to replace the expansion valve of vapor compression systems with this low-cost device that can recover expansion work that would otherwise be lost in the isenthalpic throttling process. Most of the work on vortex tubes used for refrigeration have been numerical studies, and many of them …
-
Comparative study of advanced heat pumps
… are made to the more commonly applied vapor compression systems, including those using R-134a. The study examines the effect of thermal resistances between the device and the heat rejection or heat absorption space. A cool side temperature difference between 0 and 20{dollar}\sp\circ{dollar}C …
-
Dynamic Modeling and Advanced Control of Air Conditioning and Refrigeration Systems
… that captures the dynamics of a variety of vapor compression cycles in a form amenable to controller design. These models are highly nonlinear, and require a nonlinear control strategy to attain high performance over the entire operating envelope. To this end, a gain-scheduled control approach …
Page 1 of 2