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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.

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At least 109 records · Page 6
All sourcesNASA NTRSDOE OSTI
NASA NTRS1978

Engine component improvement: JT8D and JT9D performance improvements

A feasibility analysis screening method for predicting the airline acceptance of a proposed engine performance improvement modification was developed. Technical information derived from available test data and analytical models is used along with conceptual/preliminary designs to establish the predicted performance improvement, weight and installation characteristics, the cost for new production and retrofit, maintenance cost and qualitative characteristics of the performance improvement concepts being evaluated. These results are used to arrive at the payback period, which is the time required for an airline to recover the investment cost of concept implementation, and to predict the amount of fuel saved by a performance improvement concept. The assumptions used to calculate the payback period and fuel saved are discussed. A summary of the results when the screening method is applied is presented for several representative JT8D and JT9D performance improvement concepts. An example of the input information used to develop the summary results is shown.

Gaffin, W. O.↗
NASA NTRS1978

MSFC Assessment of Owens-Illinois SUNPAK Collector Problems

An in-depth assessment is presented of problems encountered with the Owens-Illinois SUNPAK collector installed in several ERDA solar system demonstration sites. Analysis and independent tests of the collector in the MSFC Solar Simulator where the system failure conditions were duplicated are included. The basic design of the SUNPAK collector was shown to be sound; however, material limitations dictate that near-term applications constraints be recognized by system designers. MSFC recommendations were presented to ERDA in March 1977. Subsequent retrofit activity by Owens-Illinois appears to have been effective in demonstrating the integrity of the SUNPAK collector.

Wiesenmaier, B. L.↗
NASA NTRS1979

Cost analysis of hot-air solar-heating systems

Report describes results of study of two operational test sites (Huntsville, Alabama and Carlsbad, New Mexico) furnishing stimates of actual costs and potential cost savings of new and retrofit hot-air solar heating and hot-water system for single family dwellings.

Hawkins, B. J.↗
NASA NTRS1978

Solar system installation at Louisville, Kentucky

The installation of a solar space heating and domestic hot water system is described. The overall philosophy used was to install both a liquid and a hot air system retrofitted to existing office and combined warehouse building. The 1080 sq. ft. office space is heated first and excess heat is dumped into the warehouse. The two systems offer a unique opportunity to measure the performance and compare results of both air and liquid at one site.

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NASA NTRS1979

JT8D and JT9D jet engine performance improvement program. Task 1: Feasibility analysis

JT8D and JT9D component performance improvement concepts which have a high probability of incorporation into production engines were identified and ranked. An evaluation method based on airline payback period was developed for the purpose of identifying the most promising concepts. The method used available test data and analytical models along with conceptual/preliminary designs to predict the performance improvements, weight, installation characteristics, cost for new production and retrofit, maintenance cost, and qualitative characteristics of candidate concepts. These results were used to arrive at the concept payback period, which is the time required for an airline to recover the investment cost of concept implementation.

Gaffin, W. O.↗
NASA NTRS1979

Air cushion landing gear applications study

A series of air cushion landing gear (ACLG) applications was studied and potential benefits analyzed in order to identify the most attractive of these. The selected applications are new integrated designs (not retrofits) and employ a modified design approach with improved characteristics and performance. To aid the study, a survey of potential users was made. Applications were evaluated in the light of comments received. A technology scenario is developed, with discussion of problem areas, current technology level and future needs. Feasible development timetables are suggested. It is concluded that near-term development of small-size ACLG trunks, exploration of flight effects and braking are key items. The most attractive applications are amphibious with very large cargo aircraft and small general aviation having the greatest potential.

Earl, T. D.↗
NASA NTRS1978

Methanol from coal

Economic feasibility of methanol or methyl fuel produced from coal using existing technology is discussed. Other factors considered include environmental, safety, toxicity, transportation, so storage, ease of burning, and retrofitting of present boilers. Demonstrations of its uses as a boiler fuel and as a turbine fuel are cited.

Miller, D. R.↗
NASA NTRS1979

Upper-surface modifications for C sub l max improvement of selected NASA 6-series airfoils

The thickness of the upper surface of 64 airfoils was increased from the leading edge to the position of maximum thickness. The modifications were generated using a numerical optimization routine coupled with an aerodynamic analysis code. The type of modification presented can be used for aircraft design or for the retrofit of current aircraft to improve the stall characteristics and climb performance. The coordinates of the modified airfoils are presented with plots of the forward 45% of the profiles and pressure distributions for both the modified and unmodified sections at an angle of attack of 14 degrees.

Szelazek, C. A.↗
NASA NTRS1979

Design of quiet efficient propellers

A numerical computation scheme has been developed to determine the sound generated by propellers. A comparison of these calculations to the noise data taken in the flight test of a propeller driven aircraft shows good agreement. The method is then applied in a parametric study of fixed pitch propellers designed to reduce noise. All these techniques reduce noise while maintaining shaft speed so that the method presented here may be used in a retrofit option for the general aviation fleet.

Succi, G. P.↗
NASA NTRS1979

Application of a velocity-split Navier-Stokes solution technique to external flow problems

A method for solving the Navier-Stokes equations based on splitting the velocity vector into its rotational and irrotational parts has recently been applied successfully to internal flow computations. In this paper, the applicability of the method to external flows is examined by studying two model problems; laminar incompressible flow over semiinfinite and finite flat plates. For these problems the procedure accurately reproduces the known solutions and is computationally very efficient even at high Reynolds numbers. Computational aspects of the method are discussed along with the possibility of using the procedure to retrofit a viscous capability into existing transonic potential flow codes.

Dwoyer, D. L.↗
NASA NTRS1980

Solar-heating and cooling demonstration project

Florida Solar Energy Center has retrofitted office building, approximately 5,000 square feet of area, with solar heating and air-conditioning. Information on operation, installation, controls, and hardware for system is contained in 164 page report. Document includes manufacturer's product literature and detailed drawings.

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NASA NTRS1979

Engine component improvement program: Performance improvement

Fuel consumption of commercial aircraft is considered. Fuel saving and retention components for new production and retrofit of JT9D, JT8D, and CF6 engines are reviewed. The manner in which the performance improvement concepts were selected for development and a summary of the current status of each of the 16 selected concepts are discussed.

Mcaulay, J. E.↗
NASA NTRS1979

Low NO(x) heavy fuel combustor program

The 'low nitrogen oxides heavy fuel combustor' program is described. Main program objectives are to generate and demonstrate the technology required to develop durable gas turbine combustors for utility and industrial applications, which are capable of sustained, environmentally acceptable operation with minimally processed petroleum residual fuels. The program will focus on 'dry' reductions of oxides of nitrogen, improved combustor durability, and satisfactory combustion of minimally processed petroleum residual fuels. Other technology advancements sought include: fuel flexibility for operation with petroleum distillates, blends of petroleum distillates and residual fuels, and synfuels (fuel oils derived from coal or shale); acceptable exhaust emissions of carbon monoxide, unburned hydrocarbons, sulfur oxides and smoke; and retrofit capability to existing engines.

Lister, E.↗
NASA NTRS1980

Evaluation of a high performance fixed-ratio traction drive

The results of a test program to evaluate a compact, high performance, fixed ratio traction drive are presented. This transmission, the Nasvytis Multiroller Traction Drive, is a fixed ratio, single stage planetary with two rows of stepped planet rollers. Two versions of the drive were parametrically tested back-to-back at speeds to 73,000 rpm and power levels to 180 kW (240 hp). Parametric tests were also conducted with the Nasvytis drive retrofitted to an automotive gas turbine engine. The drives exhibited good performance, with a nominal peak efficiency of 94 to 96 percent and a maximum speed loss due to creep of approximately 3.5 percent.

Loewenthal, S. H.↗
NASA NTRS1980

Velocity-split Navier-Stokes solution procedure for incompressible high Reynolds number external flows

A method for solving the Navier-Stokes equations based on splitting the velocity vector into its rotational and irrotational parts was sucessfully applied to internal flow computations. The applicability of the method to external flows is examined by studying several model problems. The model problems are those of laminar and turbulent incompressible flow past a semi-infinite flat plate and laminar incompressible flow past a finite flat plate. For these problems, the procedure accurately reproduces the known solutions and is computationally very efficient even at high Reynolds numbers. Computational aspects of the method are discussed along with the possibility of using the procedure to retrofit a viscous capability into existing potential flow codes.

Dwoyer, D. L.↗
NASA NTRS1980

Solar heating and cooling demonstration project at the Florida solar energy center

The retrofitted solar heating and cooling system installed at the Florida Solar Energy Center is described. The system was designed to supply approximately 70 percent of the annual cooling and 100 percent of the heating load. The project provides unique high temperature, nonimaging, nontracking, evacuated tube collectors. The design of the system was kept simple and employs five hydronic loops. They are energy collection, chilled water production, space cooling, space heating and energy rejection. Information is provided on the system's acceptance test results operation, controls, hardware and installation, including detailed drawings.

Source record↗
NASA NTRS1980

Large-scale wind-tunnel tests of inverting flaps on a STOL utility aircraft model

A unique inverting flap system was investigated on a large scale deflected slipstream model in the Ames 40 by 80 foot wind tunnel. The subject tests utilized 33% chord double-slotted flaps on a low aspect ratio wing that was fully immersed in the propeller slipstream. Evaluation of the flap effectiveness is aided by comparisons with the results of tests of other flap systems on the same twin propeller, twin tail boom STOL utility aircraft mode. No extreme or abrupt force or moment increments were encountered when the flaps were deflected through a wide range, corresponding to the complete retraction/extension spectrum. The lift and descent capability of the inverting flaps compared very favorably with that of the other flap systems that have been tested on this model, including some with much greater mechanical complexity. As expected, the flaps caused large nose down, pitching moment increments at the high lift settings; however, the trimmed characteristics are still competitive with those obtained from the more complicated flap systems. It is believed that these flaps may have promising potential application to the design of relatively simple STOL utility aircraft with improved performance capabilities. In addition, they may merit consideration as retrofits to existing aircraft with less effective flap systems.

Feistel, T. W.↗
NASA NTRS1980

Solar heating and domestic hot water system installed at North Dallas High School

The solar energy system located at the North Dallas High School, Dallas, Texas is discussed. The system is designed as a retrofit in a three story with basement, concrete frame high school building. Extracts from the site files, specification references for solar modification to existing building heating and domestic hot water systems, drawings, installation, operation and maintenance instructions are included.

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