Browse Topic: Turboprop engines

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Advanced Exergy Analysis of an Air Craft Gas Turbine Engine at Different Power Loading Operations2019-01-18639/16/2019
The innovations in aircraft propulsion have been identified as the key parameter towards the progress in transportation. Continuous advancement in the performance and efficiency of propulsion has enabled aircraft to travel over larger distances with higher speed. Aviation is also responsible for approximately 2% of total greenhouse gas emission and is expected to grow around 3% by 2050. The present article aims to use the exergetic analysis of a turboprop engine which should be helpful in designing of such engines and also helps these engine users to regulate and select the operation modes. A gas turbine with film air cooling of turbine blades has been proposed to be the turboprop engine. The engine is analyzed on exergy point of view at different power loading operation modes and the performance is studied. Selected exergetic measures under consideration are Exergy Efficiency, Fuel Exergy Depletion Ratio, Relative Exergy Consumption Ratio, Exergetic Improvement potential and Productivity Lack ratio. The total fuel exergy depletion ratio of the turboprop engine is estimated to be around 64.7 % at 100% loading. Also, among the identified cycle components, combustion chamber is identified as the main source (~ 35%) of the exergy destruction and, thus is the biggest contributor to the overall irreversibility of the system. The exergy efficiency is observed to be minimum at 75 % mode and maximum for Take-off. The exergetic improvement potential of the thermodynamic inefficiencies increases with increase in fuel-air ratio from 75%-mode to Take-off mode. The combustor section of the engine has been identified as the greatest source of relative exergy consumption ratio (63 %) and productivity lack ratio (51 %) followed by the turbine and compressor sections (at take off mode).
Mohapatra, Alok Kumar, Hotta, Tapano, Choudhary, Tushar
UAV Ground Control StationTBMG-343285/1/2019
General Atomics Aeronautical Systems, Inc. San Diego, CA 858-762-6700
Thermoeconomic, Sustainability and Environmental Damage Cost Analysis of Air Cooled CT7-7A Turboprop Engine2018-01-07744/3/2018
The aim of this study is to investigate the overall performance (exergetic, exergoeconomic and exergoenvironmental) of CT7-7A turboprop engine manufactured by General Electric Aviation (GE Aviation) and currently used to power CN-235, a medium range transport aircraft. The investigation has been carried out using the thermoeconomic, sustainability and environmental damage cost analysis methods. The adopted turboprop engine has been investigated to observe the behaviour of various performance parameters, sustainability, emission parameters as well as cost parameters of engine. Due to ever increasing demand in air transport systems, focus has been on developing efficient and sustainable systems with lowest possible cost. In order to reduce cost & environmental effects of engine and at same time to acquire higher performance, it is necessary to understand the mechanism that can offer improvements in the engine operating and design parameters so that higher performance can be obtained. Exergetic sustainability parameters such as exergetic efficiency, exergy loss and destruction ratio, environmental damage cost, sustainability index and sustainability cost index play an important role on choice of suitable aircraft engine for operation. The methodology includes working with energy, exergy and cost balance equations and sustainability index for component-wise modelling of the whole system. The presented work analyses CT7-7A engine from all three (thermoeconomic, sustainability and environmental analysis) perspectives.
Sahu, Mithilesh Kumar, Choudhary, Tushar, Kumari, Anupam, R, Sanjay
Exergoeconomic Analysis of Air Cooled Turboprop Engine: Air Craft Application2017-01-20449/19/2017
Aircraft engines powering propulsion of the aircraft is the key component of the system. In aircraft industry it is desirable that an aircraft engines should supply high speeds (for military fighters) with low maintenance (for civil airplanes). In this regard an integration of gas turbine engines with traditional propeller has been introduced and termed as turboprop engine. In present work, a gas turbine with cooled blading has been proposed to be the turboprop engine which has been exergoeconomically analyzed to assess the performance and economics related to the proposed turboprop engine. Exergo-economic analysis is a tool which combines thermodynamic analysis and economic principles to provide information that is helpful to predict thermodynamic performance and total cost of the engine (thermal system). The methodology includes energy, exergy and cost balance equations for component-wise modelling of whole system. “Average Cost Theory” (Levelized cost) approach has been adopted to analyze the entire system exergoeconomically. The work represents the characteristics curves for exergoeconomic parameters that show graphical relationship between the engine operating parameters and exergoeconomic parameters. Present study also compares the proposed turboprop engine with the well-known T56 turboprop engine and CT7-9C turboprop engine on exergoeconomic basis.
Sahu, Mithilesh Kumar, Choudhary, Tushar, Y, Sanjay
Europe's Aerospace Industry Looking ConfidentTBMG-197556/1/2014
Talk of further consolidation within Europe’s dynamic aerospace sector has been on the lips of industry watchers for several years, but although the major European-based global players have not progressed toward further mergers, the continent’s biggest aerospace company, the former EADS, has achieved a very significant business restructuring, sweeping all its diverse companies into one giant, three-division entity, and adopting the new corporate identity of the Airbus Group.
PROPELLER SHAFT ENDS - SINGLE ROTATIONAS41F (Current)1/4/2013
E-25 General Standards for Aerospace and Propulsion Systems
The Altair/Predator B: An Earth Science Aircraft for the 21st CenturyTBMG-46048/1/2007
NASA’s Dryden Flight Research Center, Edwards, CA, has partnered with General Atomics Aeronautical Systems, Inc. (GA-ASI) of San Diego, CA, to demonstrate technologies that will expand the capabilities of remotely operated, uninhabited aircraft to perform high-altitude earth science missions. To accomplish the task, GA-ASI is developing an enlarged version of its Predator reconnaissance aircraft, the Predator B®, including an extended-wingspan Altair version for NASA, to meet these requirements.
PROPELLER SHAFT ENDS - SINGLE ROTATIONAS41E (Historical)5/3/2006
E-25 General Standards for Aerospace and Propulsion Systems
Direct Gear Design® for Automotive Applications2005-01-18174/11/2005
This paper presents Direct Gear Design - an alternative method of analysis and design of involute gears which separates gear geometry definition from tool selection to achieve the best possible performance for a particular product and application. This method has successfully been applied for a number of automotive applications. Some examples will be presented at the end of the paper.
Kapelevich, Alexander L., McNamara, Thomas M.
Universal Maintenance & Overhaul Stand for Turbo-Jet (10,000 Lbs. Thrust Class) and Turbo-Prop EnginesARP458 (Current)12/16/2002
AGE-4 Packaging, Handling and Transportability Committee
A High Efficiency Fuselage Propeller (”Fusefan”) for Subsonic Aircraft1999-01-556910/19/1999
This report proposes a new high efficiency “fuselage fan” concept of aircraft propulsion for subsonic airplanes also noted as “fusefan” (FF). The fusefan concept consists of one or two rings of swept blades rotating around the fuselage. This variable pitch fan has an important advantage in comparison with currently used turbofan engines: it dramatically increases the cross-sectional bypass area of the propulsion system by 3-5 times. As shown in the paper this propeller has an efficiency in cruise flight of 9-16% more than the current turbofan propulsion system. It also provides a large increase in static thrust (40-75%), which in turn decreases takeoff distance about 30-45%, and has a clean wing aerodynamically due to the absence of nacelles. An analysis of the benefits of the fuselage fan compared with the Advanced Turboprop Propeller (ATP) and propfan “Unducted Fan” (UDF) shows that for equal disk loading the “fuselage fan” has the following advantages: 1. The most efficient section of the blade is near the tip, from 0.7R to R (where R is radius of propeller). The fusefan has only this section and a constant load in this ring area. This in turn increases the propeller efficiency 4-6%. 2. A short blade design is required using very small blade thickness (1.5-2%), high blade sweeping, supercritical profiles, all of which combine to increase the propeller efficiency up 5% and critical propeller Mach number up to M =0.84. 3. The wing can benefit with a laminar flow system (since no wing engines are on them) which can also reduce wing drag 5-19% (total aircraft drag 2-4%). 4. The fusefan draws in air flow over the root part of the wing, thereby increasing the area of the wing and fuselage where laminar flow occurs and decreasing total drag. 5. The fusefan decreases noise. 6. The horizontal and vertical tail is located in the fusefan flow, and as such is more efficient and can be decreased in size and weight. 7. Wing engine-out propulsion and safety issues are not a factor.
Bolonkin, Alexander
A New Replaceable Contact Aircraft Power Receptacle1999-01-555410/19/1999
Airline aircraft maintenance and ground support services meet at the connection points for ground service. Ground power must be applied to the aircraft, but responsibility for the aircraft receptacle falls to aircraft maintenance. This responsibility gap is not currently being addressed by the industry. For years any difficulty in applying power to an aircraft on the ground has been blamed solely on the ground power cable or generator. Any potential problems with the receptacles was largely ignored by ground service personnel, since they are not allowed to touch the aircraft. No one thought to look closely at the receptacle as a potential source of the inability to reliably apply power to the aircraft (in fact, routine maintenance A,B,C or D maintenance did not routinely check or change the receptacle). Recently WPI Burton Electrical Engineering began an investigation into the most common problems associated with the inability to power the aircraft and found a significant number of badly worn pins in the receptacles. By means of a “No-Go” contact gage we found that nearly 95% of the aircraft on the ground at one major airport belonging to one airline had undersized contacts due to insertion wear. Undersized contacts in an aircraft receptacle will cause arcing when a line opens under load. This arcing will burn the cable or the contacts severely. This arc flame will reach temperatures of over 23,000 degrees at the receptacle contact and could result in a temperature rise at the receptacle contacts of over 2,390 degrees Fahrenheit in one minute. This paper introduces a “replaceable contact” receptacle that will allow a the airline to change out undersized contacts in a matter of minutes. This change-out of undersized contacts will avoid the arcing and resultant temperature rise as well as the lack of proper plug to receptacle contact when ground maintenance personnel attach a cable to the aircraft.
Fernald, Darrell, Shultz, Preston
GUIDE FOR DETERMINING ENGINE STARTER DRIVE TORQUE REQUIREMENTSAIR781 (Current)9/1/1994
A general discussion is presented herein, to outline the starter functions which are necessary for a successful engine start. In addition, sample calculations are included to illustrate an accepted method of determining the engine starting time from known data. Further consideration is then given to the relationship between starter torque output and engine pad strength and a generalized formula is presented for calculating the theoretical transient torque peaks for a simplified starter-engine system. Sample calculations for actual tests are included, and the results of these calculations are compared with measured values.
AE-6 Starting Systems and Auxiliary Power Committee
Single Lever Power Management of Turboprop Engines9122009/1/1991
Historically, Turboprop engines have been controlled via two levers in the cockpit -- one adjusting engine speed and the other controlling engine power. Engine power was controlled by speed lever and fuel flow (a function of power lever angle). The pilot had to adjust the speed lever to obtain the desired engine speed setting, then he would “close the loop” on torque (his primary control parameter) by watching a gage and moving the power lever angle (PLA). This resulted in significant pilot effort in readjusting the engine to different power levels/operating modes. The control system for the TPF351-20 engine, as applied to the Embraer CBA123 aircraft, is designed to reduce pilot workload by providing a single lever system that controls the engine to a torque commanded by the power lever position. This was made possible by the use of a Full-Authority Digital Engine Control (FADEC). In order to maximize the use of the FADEC in the reduction of pilot workload, it is tied via various serial data busses on the aircraft to the Air Data Computer, the Autopilot, and Engine Indication and Crew Alerting System (EICAS). These inputs allow the FADEC to schedule torque linearly versus power lever command, and to hold each engine to within 1 percent torque of each other which prevents undesirable power lever splits or aircraft yaw. The FADEC also uses the Autopilot inputs to adjust engine power during approach to keep the aircraft on the specified glide slope. Pilot workload, aircraft performance, and maintainability are significantly improved by the state-of-the-art advances made in control of turboprop engines on the TPF351-20.
Prevallet, L.C.
Analytical Methods to Predict Liquid Congealing in Ram Air Heat Exchangers During Cold Operation8914397/1/1989
RAM AIR HEAT EXCHANGERS used to cool liquids such as lube oils or Ethylene-Glycol/water solutions can be subject to congealing in very cold ambients, resulting in a loss of cooling capability. Two-dimensional, transient analytical models have been developed to explore this phenomenon with both continuous and staggered fin cores. Staggered fin predictions are compared to flight test data from the E-2C Allison T56 engine lube oil system during winter conditions. For simpler calculations, a viscosity ratio correction was introduced and found to provide reasonable cold ambient performance predictions for the staggered fin core, using a one-dimensional approach.
Coleman, Kenneth, Kosson, Robert
Propulsion-Airframe Integration for Commercial and Military Aircraft87241111/13/1987
A significant level of research is ongoing at NASA's Langley Research Center on integrating the propulsion system with the aircraft. This program has included nacelle/pylon/wing integration for turbofan transports, propeller/nacelle/ wing integration for turboprop transports, and nozzle/afterbody/empennage integration for high performance aircraft. The studies included in this paper focus more specifically on pylon shaping and nacelle location studies for turbo-fan transports, nacelle and wing contouring and propeller location effects for turboprop transports, and nozzle shaping and empennage effects for high performance aircraft. The studies were primarily conducted in NASA Langley's 16-Foot Transonic Tunnel at Mach numbers up to 1.20. Some higher Mach number data obtained at NASA's Lewis Research Center is also included.
Henderson, William P.
Some Aspects of Prop-Fan Propulsion Systems Analysis8213582/1/1982
Optimization of a Prop-Fan propulsion system for a Mach 0.8, 120 passenger commercial transport has shown the need for relatively high levels of overall pressure ratio, combustor exit temperature, propeller tip speed and propeller disk loading to achieve lowest fuel burn and direct operating costs. Comparison of this optimized Prop-Fan propulsion system with an equivalent technology turbofan showed it to have significant mission fuel burn and direct operating cost advantages.
Owens, Robert E., Ferguson, W. Wade
The Dash 8-Design Considerations8207282/1/1982
The Dash 8 is a new 36-passenger airliner designed to fulfill a broad range of Regional Transport applications beginning in 1984. This paper describes some of the factors which have directed the basic configuration and the design objectives chosen for the Dash 8 development program.
Jackson, G.R.
Commuter Turboprop Propulsion Technology8012439/1/1980
The range of sizes and types of turboprop powerplants in current commuter service are discussed. The expected growth of this transportation sector in the 80's and 90's require more efficient powerplants with better economy and fuel conservation. General Electric is conducting a Propulsion Study for NASA as part of the Small Transport Advanced Technology (STAT) program. The General Electric CT7 is used as the current modern turboprop engine baseline. Thirty- and fifty-passenger commuter aircraft were defined to illustrate the potential improvement possible with advanced turboprops. Selection studies and evaluation procedures of the cycle and advanced design features suitable for these engines are discussed.
Hirschkron, R., Warren, R.E.
Composites Structure Applications – Piper Cheyenne III8008798/1/1980
The purpose of this paper is to outline some of the applications of preimpregnated Kevlar 49 aramid fiber to replace metal and fiberglass composite assemblies for a weight reduction in the empennage. This low density-high tensile strength and modulus material was used to reduce the weight of 250 square feet of surface area by 71 pounds.
Dark, William
Profan Propulsion for Commercial Air Transports8007334/1/1980
Incorporation of an advanced technology, high-speed turboprop propulsion system into future air transports can achieve significant reductions in operating costs through large reductions in fuel consumption. Today’s turboprop systems exhibit propulsive efficiencies which are superior to current high bypass turbofans but are limited to lower cruise speeds, which are incompatible with market requirements and air traffic control environments. The propfan concept allows the superior propulsive efficiency of the turboprop to be extended to cruise speeds of the current turbofan aircraft. Fuel consumption and operating cost benefits are shown by comparison of a propfan and turbofan powered aircraft, each designed on an equal-technology and equal-mission basis. Projected 1990 time frame comparisons are also shown. The advantages of the propfan aircraft, in light of ever-increasing fuel shortages and fuel cost increases, have resulted in several NASA-sponsored research programs to verify propulsion performance and develop the required technology base. Continuation and escalation of these activities must be accomplished to ensure incorporation of the propfan into the next generation of commercial air transports.
Coussens, T.G., Tullis, R.H.
Alternative Concepts for Advanced Energy Conservative Transport Engines7605362/1/1976
Alternative engine concepts to the advanced high bypass turbofan which have promise of reducing energy consumption including regenerative cycles and other engines with heat exchangers, unconventional engine arrangements such as geared fan engines, and high disc loading turboprops. After initial screening, several concepts were selected for a systematic evaluation of the merits of each relative to a high bypass turbofan based on advanced technology consistent with the mid 1980's time period. Both mission fuel and direct operating cost for typical long range transport missions were considered in the evaluation.
Hirschkron, R., Neitzel, R. E.
The PT6 After 5 Million Hours7103852/1/1971
The first PT6A-6 turboprop engine, rated at 500 shp, was delivered in December 1963 with an initial life of 600 hr between overhauls. By early 1971, over 4000 engines had been delivered, the output had grown to 900 shp, and times between overhaul in excess of 5000 hr had been reached. The technology spawned by the PT6 has resulted in the development, by UACL, of a host of turboprop, turboshaft, and turbofan engines, along with industrial derivatives. In over 5 million hr of operation, the PT6 has clearly demonstrated how sound technology and persistent development can meet the exciting challenges of the 1970s.
Cowley, F. R.
Air Conditioning Considerations for Turboprop Commuter and Business Aircraft7002242/1/1970
The advent of turboprop-powered aircraft designed for the commuter and business aircraft market has resulted in a need for air-conditioning systems optimized to the characteristics of this class of aircraft. Relative merits of various systems are discussed with particular emphasis placed on the interface between air-conditioning and main propulsion engines. Means of conserving bleed air are covered in full recognition of the penalties associated with bleed air extraction at certain critical aircraft operating conditions. The means of properly matching the air-conditioning system to the cabin air distribution system is also briefly discussed.
Semsroth, Howard R., Kinsell, Robert C.
Accuracy in Fuel Management for General Aviation6802092/1/1968
Present fuel flow measuring systems for medium priced aircraft lack the accuracy needed for efficient flight planning and cargo weight scheduling. They also lack the means for totalizing the measurement signal to provide an accurate measure of fuel consumed or fuel remaining. A new fuel management system has been designed to use a turbine meter to measure fuel flow. Since the measuring instrument provides a digital output, flow rate can be totalized by means of a pulse counter. Therefore, in addition to rate indication, the pilot has an accurate total of fuel consumed or fuel remaining at his disposal. This paper discusses the advantages and disadvantages of existing systems and contrasts them with the turbine meter system. It also discusses fuel density changes due to temperature and fuel type and how they affect the measuring system in both piston and turbo-type aircraft.
Wilson, James C.
Growth and Operational Capabilities of the Turboprop Engine6702362/1/1967
In addition to possessing inherent characteristics of operational smoothness, long life, and high reliability, the turboprop engine has the extremely desirable feature of large growth capability in a given frame size. Whereas the reciprocating engine has been growth limited for many years, we can anticipate a large growth in power from today's engines by increasing turbine inlet temperature, improved component efficiencies, and increased engine specific flow. Considerable activity is taking place in the areas of high temperature materials, cooling of turbines and other hot end parts, and on compressor and turbine developments. This paper highlights some of this activity.
Buckner, Howard A., Van Nimwegen, Robert R.
Regenerators Enhance Patrol Aircraft Capability6501002/1/1965
This paper notes the large increase in fuel economy due to the use of the regenerative cycle, particularly at low partial power. It then examines the striking effect of using regenerative turboprop engines on the trade-off between various aspects of patrol aircraft dessign and mission capability.
Crockett, Harold B., Field, Roger E.
Application of Regenerative Engines to Current and Future Aircraft6501012/1/1965
The possibility of improving aircraft range, payload, and endurance through application of regenerative cycle engines is examined in this paper. Emphasis is placed on the reduction in propulsion system weight realizable for first and second generation aircraft of the future. Propulsion system characteristics of future regenerative and nonregenerative turboshaft, turboprop, and turbofan engines is estimated and discussed.
Sallee, G. P., Mehwald, G.
The Self-Sufficient Airplane6503242/1/1965
Various methods of starting the turbo-prop engines of the De Havilland Buffalo are discussed. As a result of the evaluation, the system adopted results in an airplane which is self-sufficient, i.e., needing no ground power for its continuing operation anywhere in the world. It is shown that this is achieved with a weight saving over other types of start systems. Advantages, economic and otherwise are discussed, and the suggestion is made that self-sufficiency is a desirable end in itself and may be applied to airline type of operations.
Cracknell, F., Barker, C. C.
Operational Employment of the Convair Charger6502342/1/1965
The Convair Model 48 Charger was successfully flown in November, marking a major milestone in development of the first airplane built specifically to operate from rough terrain in the forward combat area. Sponsored by General Dynamics Corp., this new airplane complements existing military systems by bridging the performance gap between helicopters and high-performance jets. It provides a variety of missions capabilities, including surveillance, counterinsurgency, armed reconnaissance, utility, and cargo.
Patrick, E. E.
Application of Regenerative Engines to Projected Air Force Missions6404311/1/1964
Payload and time-on-station performance of long endurance aircraft is shown for aircraft equipped with conventional and regenerative turboprop engines. Incorporation of laminar flow control on the airframe and addition of regeneration to helicopter engines is discussed; these two design considerations appreciably improve performance. Also, for helicopter missions in excess of approximately 2 hr duration, improvement in performance can be obtained by addition of regeneration process to the turboshaft engine cycle.
Brock, James E., Gershon, Isak J.
Test of a Regenerative Turboprop Aircraft Engine6404291/1/1964
A complete 5500 hp size regenerative turboprop aircraft engine was built and tested. The engine incorporated a modern, lightweight, tubular type regenerator. A reduction in specific fuel consumption of 36% compared to current production nonregenerative turboprop engines, was demonstrated at the cruise power test point. The program was significant because it was the first test of a modern, large size, regenerative turboprop engine in which the reduction in specific fuel consumption was demonstrated. The program also provided a background for Allison’s new lightweight T78 regenerative turboprop eigine.
Beam, Paul E., Cutler, Roswelt E.
Turbine Powered Transport Aircraft in the USSR6103581/1/1961
Ritchie, Donald J.
WHY SMALL ENGINES?5702241/1/1957
EDKINS, D. P., THORSON, M. H.
COMPRESSOR STALL PROBLEMS IN GAS-TURBINE-TYPE AIRCRAFT ENGINES5700201/1/1957
This paper was presented at the SAE National Aeronautic Meeting, New York, April 12, 1956. STALL of axial-flow-type compressors limits the flexibility of operation of 1- and 2-spool aircraft turbojet engines. Complete compressor stall or surge is a problem with regard to engine acceleration as well as low-and high-Mach-number flight at high altitudes. Deterioration of compressor performance due to low Reynolds numbers at extreme altitudes aggravates the stall problem. Inlet-flow distortions increase the severity of this problem, particularly for supersonic flight. Rotating stall at low values of equivalent rotative speed is a serious source of blade vibrational failure. This latter problem is also aggravated by inlet-flow distortions.
Benser, William A., Finger, Harold B.
Compressor and Turbine Matching Considerations in Turboprop Engines5700131/1/1957
MATCHING studies of three turboprop engine configurations were made for flight conditions from sea-level static to 600 mph at 40,000 ft. It is concluded that turbine frontal area, stress, and pressure ratio requirements made exhaust-area adjustment desirable. Sfc depended primarily upon flight conditions and turbine temperature, with lowest sfc occurring at highest turbine temperature, flight velocity, and altitude. Free turbines restricted turbine temperature range and produced critical turbine requirements. Increasing a two-spool engine's outer-compressor pressure ratio increased turbine temperature range and made turbine requirements less critical.
Davison, Elmer H.
PNEUMATIC vs. MECHANICAL POWER EXTRACTION FOR AIRCRAFT ACCESSORIES5602661/1/1956
McMANUS, RICHARD L.
THE VECKERS' VISCOUNT ON TRANS-CANADA AIR LINES' ROUTES5500581/1/1955
DYMENT, J. T.
FLEXIBLE SUSPENSIONS FOR TURBOPROP AND TURBOJET POWER PLANTS5501831/1/1955
The turbine power plant has inherent vibratory disturbances. It is also a fragile device. A flexible suspension holding the power plant in the airframe must protect one from the other. To do this, the suspension must control natural frequencies to limit vibration transmission, hold the power plant in the airframe through ultimate load conditions, distribute loads into a desirable pattern, maintain stability, provide adequate service life, and permit simple installation removal without size, weight, and complexity disadvantage to the installation. There are many power plant, airframe, and general installation factors which contribute to these characteristics. The use of these factors and their effect, as well as a tabulation of required data are presented.
REBMAN, JACK
CAPABILITIES AND OPERATING COSTS OF POSSIBLE FUTURE TRANSPORT AIRPLANES5401581/1/1954
JONES, T. V.
TURBO PROP CONTROLS - HOW COMPLICATED?5301731/1/1953
Controls for turbo-prop power plants must fulfill a wide variety of requirements, including both those that are fundamental to gas turbine operation and those that stem from the need to simplify airplane operation. This paper discusses these requirements and their influence on system complexity. The relationships among performance, complexity, and reliability are considered, and recommendations for future lines of development are offered.
RHINES, THOMAS B.
EFFECT OF ENGINE WEIGHT, DRAG, AND FUEL CONSUMPTION ON DIRECT OPERATING COST OF A COMMERCIAL AIRPLANE5300281/1/1953
STEINER, J. E.
The Fruits Of The Dissatisfied Engineer5100901/1/1951
HORNER, H. MANSFIELD
General Design Aspects Of Turbo-Prop & Turbo-Jet Aircraft Fuel Systems5101311/1/1951
BRANDT, C. STEWART
Production Problems of Turbojet Engines4902191/1/1949
THE production problems associated with turbojet engines are not more complex than those encountered with reciprocating engines, according to the author, but they are of a surprisingly different nature. For instance, he points out that, whereas reciprocating engine parts are made chiefly from forgings, castings, and bar stock, the major portion of the turbojet engine is welded sheet metal structure. Then, the so-called hot parts - the combustion chamber, nozzle diaphragm, turbine, and tail cone - also present entirely new problems. The control of heat distortion caused by the high temperatures and the high temperature differentials in these parts requires closer coordination with metallurgists, steel mills, forge shops, welders, and parts fabricators than is required with reciprocating engines.
McCRAE, T. S.
JET TRANSPORT JITTERS4901531/1/1949
Littlewood, William
Long-range overseas transport plane of 1955∼Powerplants∼Effect of various types4801571/1/1948
FROESCH, CHARLES
COMPLETE DESIGN PANEL WHAT WILL BE THE NUMBER, TYPE AND ARRANGEMENT OF POWERPLANTS?4801641/1/1948
ADAMS, HAROLD W.
ELECTRONIC ANALOG STUDIES FOR TURBOPROP CONTROL SYSTEMS4801921/1/1948
DESIGN of stable turboprop control systems is greatly speeded up by the WAC electronic analog. This computing device simulates the physical relationship between the five prime variables involved: speed, torque, temperature, fuel flow, and propeller blade angle. Although as many as 25 design characteristics may be involved in a control system, the analog can determine the optimum values for them in the course of one day. The analog computing technique might be equally valuable in a number of other uses.
Philbrick, G. A., Stark, W. T., Schaffer, W. C.
POWERPLANT AND EQUIPMENT PANEL - Will There Be Propellers Suitable Performance-Wise and Stress-Wise for this Transport?4801611/1/1948
Enos, Louis H.
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