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Vehicle Noise Control Engineering Academy - Vehicle Interior Noise Track

The Vehicle Noise Control Engineering Academy covers a variety of vehicle noise control engineering principles and practices. There are two concurrent, specialty tracks (with some common sessions): Vehicle Interior Noise and Powertrain Noise. Students should choose and register for the appropriate track they wish to attend. The Vehicle Interior Noise track focuses on understanding the characteristics of noise produced by different propulsion systems, including internal combustion, hybrid and electric powered vehicles and how these noises affect the sound quality of a vehicle’s interior.
Technical Paper

Gaging Airplane-Engine Performance

WHILE virtually all aircraft builders agree in placing reliability as the most important factor in gaging engine performance, from there on agreement is lacking. The author believes that all factors exclusive of reliability can be evaluated so as to provide a good basis for choosing an engine. These factors include durability, which despite the opinion of some aeronautic engineers is not synonymous with reliability; weight per horsepower of the complete powerplant, including radiators and cowling; head resistance; fuel consumption; and first cost. The effect of changes in engine weight on operating cost are discussed, the text being supplemented by tables showing the effect of increased engine-weight, operating cost and the operation-expense items that are affected.
Technical Paper


Infallible performance and economical operation are the bases of successful commercial flying. Airplanes, having passed through the experimental and demonstration periods, must now prove their usefulness. Heretofore, because of military requirements, designers have fostered the use of power rather than refinement of design to obtain performance, but commercial operation demands efficiency, and in each of the four essentials, namely, dependability, size, total powerplant weight and cost, opportunity for decided improvement still exists. The requirements and limiting factors of each of these essentials are discussed in turn and the conclusion is drawn that a relation exists between the amount of thrust delivered to the air and the weight put into an airplane for its propulsion. To obtain the best over-all performance, if these terms are considered as a fraction, the numerator should have the maximum and the denominator the minimum value.
Technical Paper


The annual report covering transportation by the largest British air-transport company laid particular emphasis upon the greater value of the faster machines in its service. Granted that efficient loads can be carried, the expense, trouble and danger of the airplane are justified only when a load is carried at far greater speed than by any other means. A reasonable conclusion seems to be that we can judge the progress made in aviation largely by the increased speed attainable. It is interesting and possibly very valuable therefore to inquire into the relations of power and resistance as applied to small racing machines with aircraft engines that are available.
Technical Paper


The paper defines properties that describe the performance of a radiator; states the effects on these properties of external conditions such as flying speed, atmospheric conditions and position of the radiator on the airplane; enumerates the effects of various features of design of the radiator core; and compares methods that have been proposed for controlling the cooling capacity at altitudes. Empirical equations and constants are given, wherever warranted by the information available.
Technical Paper


THIS paper recounts, step by step and model by model, the development of the Allison V-1710 aircraft engine - the first liquid-cooled military aircraft engine in production in this country. Since 1930, when the design of this V-type 12-cyl engine was initiated, the powerplant has been stepped up from 650 hp without supercharging to 1000-1500 hp in its supercharged state, and the weight has increased from about 1000 lb to 1320 lb, the author reveals. The following three underlying reasons are given for building the first V-1710 engine: 1. That the V-12 type of construction with its small frontal area could be installed with less drag than any other type of engine. 2. That a liquid-cooled engine could be operated at a higher power output per cubic inch due to the type and uniformity of cooling. 3. That the liquid-cooled engine would be more reliable because it is less sensitive to temporary overloads on account of the heat capacity and limiting temperatures (boiling) of the coolant.
Technical Paper


THE effects of the combustion process and detonation on internal coolants are presented here, as well as the effect of these coolants, in turn, on engine performance. Some of the conclusions reached by the author are: 1. The difference between knocking and non-knocking fuels is one of degree; most fuels show evidence of pressure differentials during the combustion process, even though audible knock is not present. 2. Complete vaporization of the internal coolant is probably not secured until combustion is under way. 3. Water suppresses detonation by slowing down the combustion time and by cooling the end portion of the charge with water vapor contained in the end portion. Alcohol follows the same pattern when added to rich mixtures; for lean mixtures the higher antiknock qualities of the alcohol introduce a new factor.
Technical Paper

Design of CROSS - FLOW HEAT EXCHANGERS from Tested Core Sections

THIS paper presents a simple and rapid method of determining the performance of cross-flow intercoolers, oil coolers, or Prestone radiators from laboratory tests of a model or basic unit of the cooler. The method lends itself equally as well to the determination of the size of a cooler of any set performance. Due to the comparative rapidity with which these calculations can be made, it becomes, with the use of this method, an easy matter to make a series of calculations to determine the relations between lengths, cooling air flow, and pressure drops, for any desired performance.
Technical Paper

The Trend in Poppet Valves

THE trend in poppet valves during the past year, like many other advances in science, Mr. Colwell points out, has been an improvement upon existing performance, rather than an entirely new development. To effect a steady improvement in existing designs, the study of fundamentals, such as grain flow, structure, forging temperatures, coolants, and interior construction, has been resorted to, and thorough research on valve steels has been carried out, he reports. In the study of valve steel, 300 analyses were examined; intensive work was done on 20; and 4 showed definite merit, he says. Grain flows in aircraft valves made by the extrusion and gather-upset processes are compared. Results of an investigation of sodium cooling and head designs of aircraft valves by means of glass valves are reported and illustrated. Four outstanding automotive valve steels are analyzed chemically and physically - Silcrome No. 1, Silcrome XB, Silcrome X-10, and Silcrome XCR. Mr.
Technical Paper

The Cowling and Cooling of Radial Air-Cooled Aircraft Engines

THIS paper presents the results of coordinated research by The Pratt & Whitney Aircraft Co. (engines), the Chance Vought Corp. (airplanes), and the U.A.T. Research Division, all subsidiaries of the United Aircraft & Transport Corp. These studies were directed toward improving the performance of airplanes through reducing the drag of radial air-cooled powerplant installations as nearly as possible to the minimum necessary for adequate cooling. The studies were supported by a considerable amount of experimental data. Extensive wind-tunnel tests provided quantitative measurements of airflow and drag for many combinations of baffles and cowling, and throughout the whole work simultaneous flight-tests checked results and contributed to the final conclusions. The successive stages of baffle development, as well as the experiments with various sizes and shapes of cowling, are discussed. The optimum combination ultimately found is described in detail.
Technical Paper

Lubrication and Cooling Problems of Aircraft Engines

THIS paper presents the problem of engine lubrication from an installation and operation standpoint with respect to starting, warm-up, and stabilized flight. It describes the manner in which these problems are solved by the latest Materiel Division lubrication system, with its oil dilution, hopper-type oil-tank, viscosity-control valve and jacketed oil coolers. It also analyzes the radiator drag and shows the magnitude of unnecessary radiator drag that may exist if the radiator is not properly designed and installed. The paper then presents a practical design method and shows a sample design calculation for a 1000-hp. engine.
Technical Paper

The Aircraft Trend in Body Design from the Aircraft Viewpoint

AIRCRAFT have taken more from automobile design than they have given, but they can now repay much of the obligation without necessarily transgressing the requirements of production economy and reasonable design stability. Some of these possibilities are: (1) Improved streamlining of necessary exposed parts, particularly underneath, and incorporation of other accessories in the general body lines. (2) Use of curved glass in the windshield and lightening of all window material. (3) Reduction of the frame to the status of an assembly unit, with structural significance only in combination with the body. (4) More effective distribution of flange material around the doors. (5) Lightening of skin by use of internal stiffeners, particularly on top. (6) Development of a smaller, more efficient radiator and lightening of various engine parts. Most important is the mental attitude behind the work.
Technical Paper


THIS paper describes the various types of radiator installations in use. Tabulated data on several makes of radiation and on successful airplane radiator installations are given. A brief review of laboratory tests is made and the features to be considered in design and manufacture are discussed. The author concludes by cautioning engineers against attempting to base new designs entirely upon experimental data, without comparing the tentative design with existing successful installations.