Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “operating costs”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 163 records · Page 9
All sourcesNASA NTRSDOE OSTI
NASA NTRS1994

Engine Seal Technology Requirements to Meet NASA's Advanced Subsonic Technology Program Goals

Cycle studies have shown the benefits of increasing engine pressure ratios and cycle temperatures to decrease engine weight and improve performance of commercial turbine engines. NASA is working with industry to define technology requirements of advanced engines and engine technology to meet the goals of NASA's Advanced Subsonic Technology Initiative. As engine operating conditions become more severe and customers demand lower operating costs, NASA and engine manufacturers are investigating methods of improving engine efficiency and reducing operating costs. A number of new technologies are being examined that will allow next generation engines to operate at higher pressures and temperatures. Improving seal performance - reducing leakage and increasing service life while operating under more demanding conditions - will play an important role in meeting overall program goals of reducing specific fuel consumption and ultimately reducing direct operating costs. This paper provides an overview of the Advanced Subsonic Technology program goals, discusses the motivation for advanced seal development, and highlights seal technology requirements to meet future engine performance goals.

Steinetz, Bruce M.↗
NASA NTRS1996

Aerospace Seal Requirements

Cycle studies have shown the benefits of increasing engine pressure ratios and cycle temperatures to decrease engine weight and improve performance of commercial turbine engines. NASA is working with industry to define technology requirements of advanced engines and engine technology to meet the goals of NASA's Advanced Subsonic Technology Initiative. As engine operating conditions become more severe and customers demand lower operating costs, NASA and engine manufacturers are investigating methods of improving engine efficiency and reducing operating costs. A number of new technologies are being examined that will allow next generations engines to operate at higher pressures and temperatures. Improving seal performance - reducing leakage and increasing service life while operating under more demanding conditions - will play an important role in meeting overall program goals of reducing specific fuel consumption and ultimately reducing direct operating costs. This paper provides an overview of the Advanced Subsonic Technology Program goals discusses the motivation for advanced seal development, and highlights seal technology requirements to meet future engine performance goals.

Steinetz, Bruce M.↗
NASA NTRS1977

Economics of modern long-haul cargo airships

The economic characteristics and historical trends of long-haul air transportation are discussed. Various published estimates of modern airship direct operating costs are presented and comparatively analyzed. The large discrepancies in these estimates are in large measure explained, allowing airship direct operating costs to be estimated with some confidence. Indirect costs are also briefly discussed. Projected airship operating costs are compared with actual costs of competing modes such as airplanes, trucks, rail, and pipelines, and it is concluded that airships cannot economically compete with other long-haul modes. Thus attention is drawn to short-haul applications of the airship; and because short-haul missions lead to vehicle requirements that are considerably different from those for long-haul missions, it is concluded that the civil airship of the future is likely to bear little resemblance to those of the past.

Ardema, M. D.↗
DOE OSTI2022

A multi-stage stochastic programming model for adaptive biomass processing operation under uncertainty

Variations of physical and chemical characteristics of biomass reduce equipment utilization and increase operational costs of biomass processing. Biomass processing facilities use sensors to monitor the changes in biomass characteristics. Integrating sensory data into the operational decisions in biomass processing will increase its flexibility to the changing biomass conditions. In this paper, we propose a multi-stage stochastic programming model that minimizes the expected operational costs by identifying the initial inventory level and creating an operational decision policy for equipment speed settings. These policies take the sensory information data and the current biomass inventory level as inputs to dynamically adjust inventory levels and equipment settings according to the changes in the biomass' characteristics. We ensure that a prescribed target reactor utilization is consistently achieved by penalizing the violation of the target reactor feeding rate. A case study is developed using real-world data collected at Idaho National Laboratory's biomass processing facility. We show the value of multi-stage stochastic programming from an extensive computational experiment. Our sensitivity analysis indicates that updating the infeed rate of the system, the processing speed of equipment, and bale sequencing based on the moisture level of biomass improves the processing rate of the reactor and reduces operating costs.

09 BIOMASS FUELS↗
NASA NTRS1995

Report of the Space Shuttle Management Independent Review Team

At the request of the NASA Administrator a team was formed to review the Space Shuttle Program and propose a new management system that could significantly reduce operating costs. Composed of a group of people with broad and extensive experience in spaceflight and related areas, the team received briefings from the NASA organizations and most of the supporting contractors involved in the Shuttle Program. In addition, a number of chief executives from the supporting contractors provided advice and suggestions. The team found that the present management system has functioned reasonably well despite its diffuse structure. The team also determined that the shuttle has become a mature and reliable system, and--in terms of a manned rocket-propelled space launch system--is about as safe as today's technology will provide. In addition, NASA has reduced shuttle operating costs by about 25 percent over the past 3 years. The program, however, remains in a quasi-development mode and yearly costs remain higher than required. Given the current NASA-contractor structure and incentives, it is difficult to establish cost reduction as a primary goal and implement changes to achieve efficiencies. As a result, the team sought to create a management structure and associated environment that enables and motivates the Program to further reduce operational costs. Accordingly, the review team concluded that the NASA Space Shuttle Program should (1) establish a clear set of program goals, placing a greater emphasis on cost-efficient operations and user-friendly payload integration; (2) redefine the management structure, separating development and operations and disengaging NASA from the daily operation of the space shuttle; and (3) provide the necessary environment and conditions within the program to pursue these goals.

Source record↗
NASA NTRS1993

Impact of composites on future transport aircraft

In the current environment, new technology must be cost-effective in addition to improving operability. Various approaches have been used to determine the 'hurdle' or 'breakthrough' return that must be achieved to gain customer commitment for a new product or aircraft, or in this case, a new application of the technology. These approaches include return-on-investment, payback period, and addition to net worth. An easily understood figure-of-merit and one used by our airline customers is improvement in direct operating cost per seat-mile. Any new technology must buy its way onto the aircraft through reduction in direct operating cost (DOC).

Kinder, Robert H.↗
NASA NTRS1975

Space shuttle

The transportation cost associated with space materials processing were studied to determine the feasibility of space manufacturing. The assumptions use to determining the cost estimates for a 12 year planning period are listed, and the orbitor is described in terms of payloads. Shuttle operational costs, ground operational costs, and nonrecurring investment and development costs were analyzed.

Source record↗
NASA NTRS1981

Study of Advanced Propulsion Systems for Small Transport Aircraft Technology (STAT) Program

Definitions of takeoff gross weight, performance, and direct operating cost for both a 30 and 50 passenger airplane were established. The results indicate that a potential direct operating cost benefit, resulting from advanced technologies, of approximately 20 percent would be achieved for the 1990 engines. Of the numerous design features that were evaluated, only maintenance-related items contributed to a significant decrease in direct operating cost. Recommendations are made to continue research and technology programs for advanced component and engine development.

Baerst, C. F.↗
NASA NTRS1990

MESSOC capabilities and results

MESSOC (Model for Estimating Space Station Operations Costs) is the result of a multi-year effort by NASA to understand and model the mature operations cost of Space Station Freedom. This paper focuses on MESSOC's ability to contribute to life-cycle cost analyses through its logistics equations and databases. Together, these afford MESSOC the capability to project not only annual logistics costs for a variety of Space Station scenarios, but critical non-cost logistics results such as annual Station maintenance crewhours, upweight/downweight, and on-orbit sparing availability as well. MESSOC results using current logistics databases and baseline scenario have already shown important implications for on-orbit maintenance approaches, space transportation systems, and international operations cost sharing.

Shishko, Robert↗
DOE OSTI2020

Electricity Pricing aware Deep Reinforcement Learning based Intelligent HVAC Control

Recently, deep reinforcement learning (DRL) based intelligent control of Heating, Ventilation, and Air Conditioning (HVAC) has gained a lot of attention due to DRL's ability to optimally control HVAC for minimizing operational cost while maintaining resident's comfort. The success of such DRL-based techniques largely depends on the articulation of the problem in terms of states, actions, and reward function. Inclusion of the electricity pricing information in the problem formulation can play an important role in saving the cost of HVAC operation. However, less attention has been given in the literature on formulating well-crafted state features based on electricity pricing. In this work, we propose an approach for training the DRL model with a specific focus on feature engineering based on electricity pricing. During training, we generate random but sufficiently realistic electricity price signals so that the pre-trained DRL model is robust and adaptive to the dynamic and variable electricity prices. The validation results are encouraging and show the potential of ≈12%-15% savings in the one day cost of HVAC operation, proving the usefulness of including electricity pricing related features as state features.

Kurte, Kuldeep↗
NASA NTRS1986

Operations and support for the next-generation space transportation system

The role of operations and support in the design of future space transportation systems (STSs) is studied. There is a need to reduce launch and operation costs for future space systems. Methods for reducing the cost of ground operations and supports for a STS are described. Technological advances such as expert systems, robotics, and sensors, and reduction in management of operations are discussed. Changes in the management of flight operations and control, from a manpower intensive monitoring to a strong vehicle autonomy, are examined. The development of equipment and procedures to improve space operations and reduce costs is analyzed. The use of a clean sheet approach for building a STS is proposed.

Sawaya, G. J.↗
NASA NTRS2017

Development of an Ultra-wide band Receiver for the North America Array

The North America Array (NAA), also known as the next-generation Very Large Array (ngVLA), is a concept for a radio astronomical interferometric array operating in the frequency range 1.2 GHz to 116 GHz and designed to provide substantial improvements in sensitivity, angular resolution, and frequency coverage while reducing operational costs compared to the current Jansky Very Large Array (JVLA). At JPL, we are designing a single receiver package designed to operate across the 8 to 48 GHz frequency range, in contrast to the current JVLA, which covers this frequency range with five receiver packages. Reducing the number of receiving systems required to cover the full frequency range would reduce operating costs. We are developing a prototype integrated feed-receiver package with a system noise temperature that meets the requirements of the ngVLA/NAA primary science programs, with a design that meets the requirement of low long-term operational costs. The receiver package being developed at JPL consists of a feed horn, low-noise amplifier (LNA), and down-converters to analog intermediate frequencies. We report on the status of this receiver package development.

Lazio, Joseph↗
DOE OSTI2022

Robust Scheduling of Networked Microgrids for Economics and Resilience Improvement

The benefits of networked microgrids in terms of economics and resilience are investigated and validated in this work. Considering the stochastic unintentional islanding conditions and conventional forecast errors of both renewable generation and loads, a two-stage adaptive robust optimization is proposed to minimize the total operating cost of networked microgrids in the worst scenario of the modeled uncertainties. By coordinating the dispatch of distributed energy resources (DERs) and responsive demand among networked microgrids, the total operating cost is minimized, which includes the start-up and shut-down cost of distributed generators (DGs), the operation and maintenance (O&M) cost of DGs, the cost of buying/selling power from/to the utility grid, the degradation cost of energy storage systems (ESSs), and the cost associated with load shedding. The proposed optimization is solved with the column and constraint generation (C&CG) algorithm. The results of case studies demonstrate the advantages of networked microgrids over independent microgrids in terms of reducing total operating cost and improving the resilience of power supply.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗
DOE OSTI2023

Stochastic scheduling for commercial building cooling systems: considering uncertainty in zone temperature prediction

Here, this paper presents the first attempt to address the uncertainty in zone temperature prediction with stochastic optimization. The uncertain zone temperature is a process uncertainty and has not been considered in the existing stochastic optimization for building control. To fill this gap, we proposed a novel formulation of stochastic optimization to handle process uncertainty in building control. Specifically, we first examined the accuracy of a typical linear model for predicting zone temperature. We then formulated the scheduling of the building cooling system as a stochastic optimization problem over a 24-hour look-ahead period to minimize the electricity cost of the studied building cooling system. After that, we applied the proposed stochastic load scheduling (SLS) to a direct expansion (DX) cooling system that serves a medium office building. Through simulation with a detailed building energy simulation software, EnergyPlus, we evaluated the operational cost and the thermal comfort compared with a deterministic load scheduling. The operation cost of scheduling was found to vary with the level of zone temperature prediction uncertainty. The proposed SLS can mitigate the impacts of uncertain zone temperature predictions on both operational cost and thermal comfort. The evaluation results indicate that the proposed SLS works better when the uncertainty level is more significant.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
NASA NTRS1997

Spacecraft Demand Access: Autonomy for Low-Cost Planetary Operations

In this paper we describe a new concept and prototype for dramtically reducing the cost of contact with planetary spacecraft. Known as spacecraft Demand Access, a suite of spacecraft and ground automation technologies, it enables future intelligent spacecraft to act as initiators of cost effective contact with the ground - doing it only when necessary.

Low cost planetary operations Spacecraft Demand Ac↗
NASA NTRS1994

Central coast designs: The Eightball Express. Taking off with convention, cruising with improvements and landing with absolute success

The airline industry is very competitive, resulting in most U.S. and many international airlines being unprofitable. Because of this competition the airlines have been engaging in fare wars (which reduce revenue generated by transporting passengers) while inflation has increased. This situation of course is not developing revenue for the airlines. To revive the airlines to profitability, the difference between revenue received and airline operational cost must be improved. To solve these extreme conditions, the Eightball Express was designed with the main philosophy of developing an aircraft with a low direct operating cost and acquisition cost. Central Coast Designs' (CCD) aircraft utilizes primarily aluminum in the structure to minimize manufacturing cost, supercritical airfoil sections to minimize drag, and fuel efficient engines to minimize fuel burn. Furthermore, the aircraft was designed using Total Quality Management and Integrated Product Development to minimize development and manufacturing costs. Using these primary cost reduction techniques, the Eightball Express was designed to meet the Lockheed/AIAA Request for Proposal (RFP) requirements of a low cost, 153 passenger, 3000 nm. range transport. The Eightball Express is able to takeoff on less than a 7000 ft. runway, cruise at Mach 0.82 at an altitude of 36,000 ft. for a range of 3,000 nm., and lands on a 5,000 ft. runway. lt is able to perform this mission at a direct operating cost of 3.51 cents/available seat mile in 1992 dollars while the acquisition cost is only $28 million in 1992 dollars. By utilizing and improving on proven technologies, CCD has produced an efficient low cost commercial transport for the future.

Davis, Ryan Edwin↗