STV engine design considerations

The topics covered include the following: (1) engine design criteria and issues; (2) design requirements for man rating; (3) test requirements for man rating; (4) design requirements for space basing; (5) engine operation requirements; (6) health monitoring; (7) lunar transfer vehicle (LTV) feed system; (8) lunar excursion vehicle (LEV) propellant system; (9) area ratio gimbal angle limits; (10) reaction control system; and (11) engine configuration and characteristics. This document is presented in viewgraph form

Mechatronics & the cloud

Conventionally, the engineering design process has assumed that the design team is able to exercise control over all elements of the design, either directly or indirectly in the case of sub-systems through their specifications. The introduction of Cyber-Physical Systems (CPS) and the Internet of Things (IoT) means that a design team’s ability to have control over all elements of a system is no longer the case, particularly as the actual system configuration may well be being dynamically reconfigured in real-time according to user (and vendor) context and need. Additionally, the integration of the Internet of Things with elements of Big Data means that information becomes a commodity to be autonomously traded by and between systems, again according to context and need, all of which has implications for the privacy of system users. The paper therefore considers the relationship between mechatronics and cloud-basedtechnologies in relation to issues such as the distribution of functionality and user privacy

System controls challenges of hypersonic combined-cycle engine powered vehicles

Hypersonic aircraft with air-breathing engines have been described as the most complex and challenging air/space vehicle designs ever attempted. This is particularly true for aircraft designed to accelerate to orbital velocities. The propulsion system for the National Aerospace Plane will be an active factor in maintaining the aircraft on course. Typically addressed are the difficulties with the aerodynamic vehicle design and development, materials limitations and propulsion performance. The propulsion control system requires equal materials limitations and propulsion performance. The propulsion control system requires equal concern. Far more important than merely a subset of propulsion performance, the propulsion control system resides at the crossroads of trajectory optimization, engine static performance, and vehicle-engine configuration optimization. To date, solutions at these crossroads are multidisciplinary and generally lag behind the broader performance issues. Just how daunting these demands will be is suggested. A somewhat simplified treatment of the behavioral characteristics of hypersonic aircraft and the issues associated with their air-breathing propulsion control system design are presented

Laser Atmospheric Wind Sounder (LAWS) phase 1. Volume 2

This report summarizes and documents the results of the 12-month phase 1 work effort. The objective of phase 1 was to establish the conceptional definition of the laser atmospheric wind sounder (LAWS) sensor system, including accommodations analyses to ensure compatibility with the Space Station Freedom (SSF) and the Earth Observing System (EOS) Polar Orbiting Platform (POP). Various concepts were investigated with trade studies performed to select the configuration to be carried forward to the phase 2 Preliminary Design Definition. A summary of the LAWS system and subsystem trade studies that were performed leading to the baseline design configuration is presented in the appendix. The overall objective of the LAWS Project is to define, design, and implement an operational space based facility, LAWS, for accurate measurement of Earth wind profiles. Phase 1 addressed three major areas: (1) requirements definition; (2) instrument concepts and configurations; and (3) performance analysis. For the LAWS instrument concepts and configurations, the issues which press the technological state of the art are reliable detector lifetime and laser performance and lifetime. Lag angle compensation, pointing accuracy, satellite navigation, and telescope design are significant technical issues, but they are considered to be currently state of the art. The primary issues for performance analysis concern interaction with the atmosphere in terms of backscatter and attenuation, wind variance, and cloud blockage. The phase 1 tasks were formulated to address these significant technical issues and demonstrate the technical feasibility of the LAWS concept. Primary emphasis was placed on analysis/trade and identification of candidate concepts. Promising configurations were evaluated for performance, sensitivities, risks, and budgetary costs. Lockheed's baseline LAWS configuration is presented

Mechanical Design and Analysis of a Discrete Variable Transmission System for Transmission-Based Actuators

Over the past few years, replacing the hydraulic servo actuators with their electrical counter parts for robotics and remote handling systems has been an active field of research. These systems are of particular interest for tasks involved with the US Department of Energy, where the level of radiation exposure is high and the tasks are highly repetitive. With the hydraulic servo actuators, one is concerned with the issues like the high complexity, cost of the system and the difficulty of maintenance of the system. For high payload operations, the hydraulic systems provide an order of magnitude increase in the power density, which is almost impossible to achieve using the electrical servo actuators. Hence, for the electrical servo actuators to be used for high payload operations, the fundamental issue concerning the power and torque density must be addressed. Previous research conducted on this front suggested the use of a variable speed transmission system to spread the servomotor’s torque-speed characteristics across a wider output speed range. This has the effect of allowing smaller high power motors to also deliver high torques at low speeds. By using a variable speed transmission, the motor size can be reduced dramatically while increasing the overall actuator power density in the process. This work goes further into the detailed design of the discrete variable transmission system. A three-stage planetary gear transmission system is considered for the analysis and design. With the use of the three-stage planetary gear transmission, there are a complex and varied design issues involved. Selecting a configuration for the transmission is the first question to be answered. With the given configuration, and the ratios required the individual gears have to be sized accordingly. Other design elements involve the design of the shafting, achieving the desired configuration, bearings, housing and the design of a gear shifting mechanism. A detailed kinematic and dynamic analysis of the entire gear system is required for the design of the various components mentioned above. Analytical results are presented along with a computer-aided analysis of the work using the Pro-Engineer design and analysis software. Future work on this will be to turn this into a commercially available system, which comes down to optimizing the current design. Possibilities of optimization for the current design will be identified. A discussion on the prototype evaluation of the transmission system along with a sample test result is presented

Optimal Configuration and Sizing of Seaport Microgrids including Renewable Energy and Cold Ironing—The Port of Aalborg Case Study

Microgrids are among the promising green transition technologies that will provide enormous benefits to the seaports to manage major concerns over energy crises, environmental challenges, and economic issues. However, creating a good design for the seaport microgrid is a challenging task, considering different objectives, constraints, and uncertainties involved. To ensure the optimal operation of the system, determining the right microgrid configuration and component size at minimum cost is a vital decision at the design stage. This paper aims to design a hybrid system for a seaport microgrid with optimally sized components. The selected case study is the Port of Aalborg, Denmark. The proposed grid-connected structure consists of renewable energy sources (photovoltaic system and wind turbines), an energy storage system, and cold ironing facilities. The seaport architecture is then optimized by utilizing HOMER to meet the maximum load demand by considering important parameters such as solar global horizontal irradiance, temperature, and wind resources. Finally, the best configuration is analyzed in terms of economic feasibility, energy reliability, and environmental impacts

PrandtlPlane High–Lift System Preliminary Aerodynamic Design

An analysis of low-speed aerodynamics for an unconventional aircraft configuration has been carried out. This configuration, named Prandtlplane, implements Prandtl's Best Wing System for low induced drag. The state of the art of high-lift systems on civil aircraft and their historical trends have been reviewed in order to correctly identify the issues to be addressed. Lift requirements suitable to the investigated unconventional configuration have been assessed and several prospective high lift system layouts have been screened against these criteria. A suite of aerodynamic design tools and procedures has been assembled, thoroughly validated and applied to the analysis and modification of the selected low speed configurations. Preliminary results concerning the peculiar high-lift aerodynamics of the Prandtlplane have been summarized and recommendations for further investigations have been made

Thruster configurations for maneuvering heavy payloads

The cargo transfer vehicle (CTV) will be required to perform six degree of freedom (6DOF) maneuvers while carrying a wide range of payloads varying from 100,000 lbm to no payload. The current baseline design configuration for the CTV uses a forward propulsion module (FPM) mounted in front of the payload and the CTV behind the payload so that the center of gravity (CG) of the combined stack is contained between the thruster sets. This allows for efficient rotation and translations of heavy payloads in all directions; however, the FPM is a costly item, so it is desirable to find design solutions which do not require the FPM. This presentation provides an overview of the work performed in analyzing the FPM requirements for the CTV. Specifically, key issues related to thruster configuration requirements for operating the CTV without the FPM, throughout the 100,000 lbm payload to no payload range, will be highlighted. In this study, only the reaction control system (RCS) thruster configurations are considered and the orbit adjust engines are not addressed. An important output of this study is the viable alternative thruster configurations which eliminate the need for the FPM. Initial results were derived using analytical techniques and simulation analysis tools. Results from the preliminary analysis were used as inputs for our 6DOF simulation. The 6DOF simulation was used to validate our design guidelines and to verify the performance of the thruster configurations