Search results for "Piston"

The Rotary Aero Engine from 1908 to 1918

2012

The rotary aero engine is a special type of air-cooled radial engine, where the cylinders are arranged like the spokes of a wheel and turn around the crankshaft. The propeller is connected to the cylinders, while the crankshaft is fixed to the frame. The rotary aero engine, developed in 1908, set new standards of power and light weight within the aircraft industry. It was adopted by many pioneer aviators and widely used to set records of endurance, speed and height. Many aero engine manufacturers produced different models and variants of this type of engine, which was extensively used until the end of the First World War. The latest evolution of the rotary engine was the counter-rotary arra…

A Study on the Use of Combustion Phase Indicators for MBT Spark Timing on a Bi-Fuel Engine

2007

The performance of a spark ignition engine strongly depends on the phase of the combustion process with respect to piston motion, and hence on the spark advance; this fundamental parameter is actually controlled in open-loop by means of maps drawn up on the test bench and stored in the Electronic Control Unit (ECU). Bi-fuel engines (e.g. running either on gasoline or on natural gas) require a double mapping process in order to obtain a spark timing map for each of the fuels. This map based open-loop control however does not assure to run the engine always with the best spark timing, which can be influenced by many factors, like ambient condition of pressure, temperature and humidity, fuel p…

Force Variations on Heave Compensating System for Ultra-Deepwater Drilling Risers

2010

This paper discusses modeling aspects related to dynamic analysis of deep water drilling risers. These risers must have a heave compensator that maintains a near constant tension in the riser independent on platform motions. Traditional riser analysis will apply constant top tension or a simple parametric model that may give approximate tension variation. The present paper describes an alternative analysis procedure that consists of the following step: • Global riser analysis including calculation of dynamic stroke of the heave compensator from platform motions and riser dynamics. A “pipe-in-pipe” approach is used to represent the hydraulic cylinders. • Calculation of dynamic tension variat…

An analytical approach for the evaluation of the optimal combustion phase in spark ignition engines

2009

It is well known that the spark advance is one of the most important parameters influencing the efficiency of a spark ignition engine. A change in this parameter causes a shift in the combustion phase, whose optimal position, with respect to the piston motion, implies the maximum brake mean effective pressure for given operative conditions. The best spark timing is usually estimated by means of experimental trials on the engine test bed or by means of thermodynamic simulations of the engine cycle. In this work, instead, the authors developed, under some simplifying hypothesis, an original theoretical formulation for the estimation of the optimal combustion phase. The most significant parame…

Tietue 2011/3

2011

Jyväskylän tieteellinen kirjasto : katsaus sen syntyyn ja kehitykseen

1927

Jyväskylän tieteellinen kirjastotoimi 85 vuotta

1997

Intermezzo - Jyväskylän kirjastojen musiikkiaineistot

2003

Jyväskylän kirjastojen ja kaupungin opetuspalvelujen suunnitelma informaatiolukutaidon edistämisestä

2011

Idea kotilon kuoressa : Alvar Aallon kampuskappelisuunnitelman muotoutuminen

2023

Artikkelissa tarkastellaan kampuskappelisuunnitelmaa, jonka Jyväskylän kasvatusopillisen korkeakoulun ylioppilaskunta tilasi arkkitehti Alvar Aallolta (1898–1976) vuonna 1961. Kappeli oli tarkoitus rakentaa vuoden 1964 lopulla valmistuneen ylioppilastalon osaksi. Kyseessä on taidehistoriallinen tapaustutkimus, erityisesti eri prosessivaiheista muodostuvan suunnittelukokonaisuuden selvitys. Artikkelissa tarkastellaan Aallon toimiston laatimia neljänlaisia luonnoksia kiinnittäen huomiota kappelin sijaintiin, muotoon, ja sisätilaratkaisuihin. Tutkimus osoittaa, miten määrätietoisesti Alvar Aalto piti kiinni arkkitehtonisen ja kaupunkikuvallisen näkemyksensä säilymisestä projektin edetessä. Kap…