The atmosphere of Mars - A derivation of engineering and design parameters.
Atmosphere of Mars studied using three models generated to show high, mean and low density compositions to account for gravitational and magnetic fields
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Atmosphere of Mars studied using three models generated to show high, mean and low density compositions to account for gravitational and magnetic fields
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Computerized simulation for predicting air transportation in United States for 1980
Design of test facility and prototype fan for turbofan acoustic research
Possibilities were examined for improving agricultural productivity through the application of aerospace technology. An overview of agriculture and of the problems of feeding a growing world population are presented. The present state of agriculture, of plant and animal culture, and agri-business are reviewed. Also analyzed are the various systems for remote sensing, particularly applications to agriculture. The report recommends additional research and technology in the areas of aerial application of chemicals, of remote sensing systems, of weather and climate investigations, and of air vehicle design. Also considered in detail are the social, legal, economic, and political results of intensification of technical applications to agriculture.
A mixed exhaust, direct drive fan turbofan configuration was selected from four candidates. This choice was based on its ability to exceed study goals of 12% lower thrust specific fuel consumption and 5% lower direct operating cost by the 1990's with commercially acceptable technical risk and relative mechanical simplicity. The evaluation leading to configuration selection is discussed. Necessary technology advancements are identified and related to the goals.
The national air cargo system is analyzed and how it should be in 1990 is prescribed in order to operate successfully through 2015; that is through one equipment cycle. Elements of the system which are largely under control of the airlines and the aircraft manufacturers are discussed. The discussion deals with aircraft, networks, facilities, and procedures. The regulations which govern the movement of air freight are considered. The larger public policy interests which must be served by the kind of system proposed, the air cargo integrated system (ACIS), are addressed. The possible social, economical, political, and environment impacts of the system are considered. Recommendations are also given.
Mechanical and thermal properties, not available in the literature but necessary to structural design, using thallium doped sodium iodide and sodium doped cesium iodide were determined to be coefficient of linear thermal expansion, thermal conductivity, thermal shock resistance, heat capacity, elastic constants, ultimate strengths, creep, hardness, susceptibility to subcritical crack growth, and ingot variation of strength. These properties were measured for single and polycrystalline materials at room temperature.
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The primary goal was to address specific needs in the design of an integrated system to grow higher plants in space. With the needs defined, the emphasis was placed on the design and fabrication of devices to meet these needs. Specific attention was placed on a hand-held harvester, a nutrient concentration sensor, an air-water separator, and a closed-loop biological system simulation.
Design of successful airbreathing engines for operation at near-orbital speeds presents significant challenges in all the disciplines involved, including propulsion. This paper presents a discussion of the important physics of hypersonic combustion and an assessment of the state of the art of ground simulations with pulse facilities and with computational techniques. Recent examples of experimental and computational simulations are presented and discussed. The need for continued application of these tools to establish the credibility and fidelity of engineering design methods for practical hypersonic combustors is emphasized along with the critical need for improved diagnostic methods for hypervelocity reacting flows.
A study is presented that assesses the feasibility of (1) using common nuclear thermal rocket (NTR) vehicle components to perform a wide range of lunar and Mars missions, and (2) potential performance gains achieved via 'dual-mode' NTR operation, where the nuclear reactor is utilized not only for propulsion but also for electrical power generation. Four vehicle configurations are considered, modular designs with multiple single engine modules and single engine designs with multiple propellant tanks. The standard tank sizes arrived at in the Mars mission mass performance calculations are then applied to cargo and piloted lunar craft to evaluate lunar NTR mass performance against that for chemical propulsion.
When it is required to define the cycle parameters and calculate the performance of a real engine, there are numerous practical constraints that need to be taken into account. These fall into two main categories: the limitations of available component technologies, and the operational considerations that are dependent on aircraft application. The lecture discusses the main technology limiters and indicates how they are incorporated into the cycle definition process. Operational factors include the extent of the intended flight envelope and range of critical flight conditions for which performance must be assured, and the balance to be struck between minimising fuel consumption, maximising installed power and constraining costs of ownership. Taking these technology and operational influences into account, the basic cycle characteristics and approach to cycle choice are examined for three main classes of aircraft: subsonic transports, military combat aircraft and helicopters.
The space shuttle main engine, full flow staged combustion, integrated modular engine concept, split expander, and expander bleed rocket engine cycles were studied for use on Single-Stage-to-Orbit fully reusable vehicles. The vehicle uses vertical take-off and horizontal landing and liquid hydrogen rockets for propulsion. The PROPSIZE computer code was modified for use on the available computers. Vehicle sizing was done after trajectory optimization for various engine designs. The various rocket engine cycles were compared and it was found that the full flow staged combustion cycle had the lowest vehicle dry mass. The split expander cycle could have advantages in safety and cooling which could make it the preferred choice in some cases. Comparison to previous work with two-stage heavy-lift vehicles showed that the same ranking of the cycles was found for both vehicle concepts.
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Thermal barrier coatings (TBC's) have been used in high thrust aircraft engines for many years, and have proved to be very effective in providing thermal protection and increasing engine efficiencies. TBC life requirements for aircraft engines are typically less than those required for industrial gas turbines. This paper describes current and future applications of TBC's in industrial gas turbine engines. Early testing and applications of TBC's is reviewed. Areas of concern from the engine designer's and materials engineer's perspective are identified and evaluated. This paper focuses on the key factors that are expected to influence utilization of TBC's in advanced industrial gas turbine engines. It is anticipated that reliable, durable and highly effective coating systems will be produced that will ultimately improve engine efficiency and performance.
This paper presents viewgraphs on Solar Thermal Propulsion (STP). Some of the topics include: 1) Ways to use Solar Energy for Propulsion; 2) Solar (fusion) Energy; 3) Operation in Orbit; 4) Propulsion Concepts; 5) Critical Equations; 6) Power Efficiency; 7) Major STP Projects; 8) Types of STP Engines; 9) Solar Thermal Propulsion Direct Gain Assembly; 10) Specific Impulse; 11) Thrust; 12) Temperature Distribution; 13) Pressure Loss; 14) Transient Startup; 15) Axial Heat Input; 16) Direct Gain Engine Design; 17) Direct Gain Engine Fabrication; 18) Solar Thermal Propulsion Direct Gain Components; 19) Solar Thermal Test Facility; and 20) Checkout Results.