1,721,272 research outputs found
General layout characteristics and performance of a new wind tunnel for aerodynamic and functional tests on full-scale vehicles
No full textThis paper discusses the advantages of closed type and open type working sections of a wind tunnel designed for aerodynamic tests on full-scale vehicles. Analyses of economic considerations, component efficiency, and applicability to the specific purpose of testing were the deciding factors in choosing the open type working section for this wind tunnel being erected by Pininfarina at Torino, Italy. Preliminary design work and supporting research are described
Variable mass crankshaft for general car performance improvement: acceleration, fuel economy and emissions
No full textA passenger car variable mass crankshaft is here reported. This particular device consists of an auxiliary flywheel with a high moment of inertia. It spins freely at above 1500 rpm, thanks to centrifugal masses which disengaged it from the crankshaft. The flywheel is connected once again to the crankshaft, when the engine speed reduces to under 1400 rpm. In this way, the mass of the crankshaft is increase at low engine speed (e.g. idle condition) and the magnitude of rotational fluctuations are consequently lowered. On the contrary, the extra mass is unnecessary and undesirable above certain engine speed and is therefore reduced, so improving both the vehicle acceleration, engine braking performance and fuel economy. He variable mass crankshaft device has been mounted onto a passenger car, in order to determine fuel consumption and acceleration performance, both though theoretical investigations and by means of experimental tests on roller-type bench
Education and research on automotive engineering at the Turin Institute of Technology
No full textThis paper refers to a previous report presented at th FISITA Congress in Dearborn (USA) dealing with Educational and Training on Automotive Engineering at the Turin Institute of Technology (Politecnico di Torino). This paper is more specifically intended as a description of the research work carried out by both students and young graduates during the concluding period of graduate and post-graduate studies, under their teacher’s guidance. Some examples of research programmes following the direct experience of the authors, including those starting from thesis or dissertations, which contribute success of the programmes themselves, are described. Among these the following are cited and briefly examined: Full scale automotive wind tunnel, Variable valve-timing system for s.i. engine, Indoor tire testing-facility and fallouts. Finally, the way different contributions which come from University, Industry and independent Research Centres should be managed and connected, is considered and discusse
On the directional stability of motor cars when approaching and exceeding the adhesion limits between tire and ground
No full textThis paper is concerned with the investigation of the directional phenomena occurring when the limit of adhesion of tires to the ground is reached or overcome. To this purpose, an original mathematical model assuming the car as a system with six degrees of freedom was first developed. The mathematical model includes a model simulating the tire-ground mechanism through which the tangential forces are developed also when the limit of adhesion is exceeded. In the mean time, an original test car was designed and built in order to compare the actual behavior of the car on the road with that of the model. Much of the research time was devoted to checking and setting up the mathematical model for a correct simulation of the behavior of the car on the road. Thereafter, the mathematical model was used alone to determine time histories of important variable of the motion and parameters as lateral attitude, ground-wheel forces, over-steer-under-steer degree etc., describing the directional behavior of the car during exceptional situation as, for instance, the “tête à queue”
Influenza della direzione di scuotimento della ruota nel comportamento della sospensione degli autoveicoli
No full textVengono riportati i primi risultati di un lavoro sperimentale tendente a valutare l'influenza della direzione di scuotimento della ruota sul comportamento della sospensione degli autoveicoli. A tal fine é stato usato un carrello monoruota trainato su di un ostacolo dinamometrico da un'autovettura per indagare sulle azioni longitudinali impresse ad una ruota pneumatica in rotolamento e sul loro effetto sulla massa sospesa e sulla massa non sospesa, al variare appunto della direzione di scuotiment
Automobile Aerodynamic Drag on the Road Compared With Wind Tunnel Tests
No full textThis investigation was performed with the purpose of comparing the arodynamic drag of an automobile as measured in a full-scale wind tunnel with the drag as measured on the road. A definition of the drag coefficient as measured both on the road and in the wind tunnel is given in advance in order to allow a comparison to be made between the two operating conditions. Three medium size european cars were selected, one notch-back type and two hatch-back types. Road testing was mainly based on the coast-down method. The total resistance was determined by statistical analysis of the experimental results. The theoretical basis and the specifications of the procedure are investigated and justified. Additional outdoor and indoor tests were carried out in order to isolate the aerodynamic drag. The wind tunnel tests were conducted on the same cars fully equipped as tested on the road and in the same speed range. The wind tunnel tests being executed at steady speeds, however, supplementary road tests were performed in order to determine the effect of the deceleration on the aerodynamic drag. The final results show only small differences between the aerodynamic drag coefficients as measured in the wind tunnel and on the road with the procedure here described
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
- …
