Preliminary Design Study of an Enhanced Mixing Eductor System for the LHA (R) Gas Turbine Exhaust


Book Description

A preliminary design study was conducted to determine the geometry for an enhanced mixing eductor system for the Landing, Helicopter Assault Ship Replacement (LHAR) program gas turbine exhaust. A one-dimensional analytical model, with a correction factor applied to the secondary mass flow, was developed to predict the secondary air mass flow rate and the exhaust temperature at the mixing tube exit plane. The resultant design consisted of a high aspect ratio lobed nozzle and a mixing tube. The model was also used to predict the backpressure developed by the ducting configuration. The proposed design resulted in a 50% reduction in exhaust temperature with only a 6 inch H2O increase in back pressure. A detailed design of the oval-to-rectangular transition duct is provided, based on empirical data from a similar duct design. The study also included a prediction of plume radiation intensity in the 3-5 micron band for various aspect ratio slots.




The Design of High-Efficiency Turbomachinery and Gas Turbines, second edition, with a new preface


Book Description

The second edition of a comprehensive textbook that introduces turbomachinery and gas turbines through design methods and examples. This comprehensive textbook is unique in its design-focused approach to turbomachinery and gas turbines. It offers students and practicing engineers methods for configuring these machines to perform with the highest possible efficiency. Examples and problems are based on the actual design of turbomachinery and turbines. After an introductory chapter that outlines the goals of the book and provides definitions of terms and parts, the book offers a brief review of the basic principles of thermodynamics and efficiency definitions. The rest of the book is devoted to the analysis and design of real turbomachinery configurations and gas turbines, based on a consistent application of thermodynamic theory and a more empirical treatment of fluid dynamics that relies on the extensive use of design charts. Topics include turbine power cycles, diffusion and diffusers, the analysis and design of three-dimensional free-stream flow, and combustion systems and combustion calculations. The second edition updates every chapter, adding material on subjects that include flow correlations, energy transfer in turbomachines, and three-dimensional design. A solutions manual is available for instructors. This new MIT Press edition makes a popular text available again, with corrections and some updates, to a wide audience of students, professors, and professionals.










Performance Exhaust Systems


Book Description

To extract maximum performance, an engine needs an efficient, well-designed, and properly tuned exhaust system. In fact, the exhaust system's design, components, and materials have a large impact on the overall performance of the engine. Engine builders and car owners need to carefully consider the exhaust layout, select the parts, and fabricate the exhaust system that delivers the best performance for car and particular application. Master engine builder and award-winning writer Mike Mavrigian explains exhaust system principles, function, and components in clear and concise language. He then details how to design, fabricate, and fit exhaust systems to classic street cars as well as for special and racing applications. Air/exhaust-gas flow dynamics and exhaust system design are explained. Cam duration and overlap are also analyzed to determine how an engine breathes in air/fuel, as the exhaust must efficiently manage this burned mixture. Pipe bending is a science as well as art and you’re shown how to effectively crush and mandrel bend exhaust pipe to fit your header/manifold and chassis combination. Header tube diameter and length is taken into account, as well as the most efficient catalytic converters and resonators for achieving your performance goals. In addition, Mavrigian covers the special exhaust system requirements for supercharged and turbocharged systems. When building a high-performance engine, you need a high-performance exhaust system that’s tuned and fitted to that engine so you can realize maximum performance. This comprehensive book is your guide to achieving ultimate exhaust system performance. It shows you how to fabricate a system for custom applications and to fit the correct prefabricated system to your car. No other book on the market is solely dedicated to fabricating and fitting an exhaust system in high-performance applications.




Preliminary Design of an Advanced Exhaust Gas Diverter


Book Description

The report contains results of a design study program for an advanced device for the diversion of high energy gas generator turbine discharge gases. Numerous concepts of such devices were initiated during the preliminary period. Evaluation of these concepts resulted in the selection of two design approaches for further design studies. One design, a basic butterfly valve, embodies significant improvements over the current type. The second design represents a unique concept which uses a rotating elbow enclosed within a housing to achieve gas flow diversion. An analysis and comparison of the two designs brought about the selection of the butterfly approach for the preparation of a final design and for the preparation of manufacturing drawings. A manufacturing plan describing the processes and methods which would be required to fabricate a prototype version of the butterfly valve is included. (Author).







Design of an Exhaust Gas Energy Recovery System for Internal Combustion Engines


Book Description

The current research paper presents the experimental findings following exhaust runner heat exchanger tests as well as a realistic theoretical proof of concept for steam turbocharging by using said results. A preliminary heat analysis was completed in order to first assess the magnitude of recoverable energy from the spent exhaust gases. Through experimentation, actual heat absorbed by the water was successfully obtained and was higher than predicted. The proof of concept was then completed by inputting the experimental engine parameters into a turbocharged Otto cycle combined to a Rankine cycle using experimental figures for the heat input stages of the assessment. The theory ultimately resulted in peak improvements of 7.446% in engine thermal efficiency and an interesting reduction in brake specific fuel consumption of 6.930% near 2500 RPM. Furthermore, through the use of steam turbocharging, brake engine power can theoretically be improved by 35.00%, resulting in a 13.73% increase in the current experimental engine’s power density. The test engine was mounted onto a hydraulic engine dyno and a baseline of its power and torque output was recorded for final confirmation that the heat recuperated via this energy recovery system was not being negated elsewhere in the combined cycle. Finally, a preliminary steam turbine was designed and the optimal system configuration was presented for future use. The obtained results clearly demonstrate that steam turbocharging is a novel energy recovery system with great potential.