The latest publications in this offer are:
Aerospace propulsion systems (for aircraft, space launchers, missiles, probes, satellites, etc.) are mostly of two types; reactors and propellers. This article presents several categories of propulsion systems and defines the main quantities used in the domain of the propulsion, such as specific impulse and constructive index. The main industrial trends are also presented.
Aerospace propulsion is based upon models and physical laws which govern the movement and speed of flying systems. This article details the various formulae and laws to be mastered (Bréguet and Tsiolkovski formulae for instance) in order to design a propulsion system efficiently. It provides the way of using estimates, reference levels and simplified design laws for a cruise, an acceleration, a ballistic flight initially propelled. The understanding of these various data facilitates the acquisition of certain calculation "reflexes". In order to gain a sound knowledge of these elements, certain exercises of application (antitank missiles, launcher restitution) are also explained in this article.
Several systems of aerospace propulsion are available and the choice is made according to the desired usage. Engines are classified according to several criteria: technological, functional, or even according to the chemical process of the reaction. This article presents the main type of propulsion systems (turboprops, propellers, ramjets, turbojet and urbofan, pulsed detonation engines, turbo rockets, etc.) as well as certain of their characteristics (type of reaction, area of use, domain of Mach number, etc.). As an example, it more specifically focuses on the choice of propulsion for missiles (anti-missiles, anti-ships, etc.) according to the type of mission carried out.
Several types of space propulsion exist according to the way the propulsive mass is accelerated. Regardless of the chosen method, designing propulsion systems involves several mechanical principles and theories. The dimensioning and production of the propulsion system requires the knowledge and mastery of mathematical and physical tools. This article thus reviews the essential notions of the flight (regime, standard atmosphere, etc.), the aerodynamic and thermodynamic formulae which are used in propulsion in the planning stages, as well as the various level of air and combustion modeling.
After a reminder of the classification of piston engines, this article focuses on the essential decarbonization of thermal machines by 2030 and beyond. The technological issues that govern the innovations of progress in hydrocarbon-free combustion engines are reviewed. The reactivation of old concepts of alternative engines appropriate to this new context concludes the discussion.
Dihydrogen is a central axis of the decarbonized energy revolution of fixed energy conversion machines and mobility. The detonic equations make it possible to understand and identify the major risks of leakage and explosion of this molecule. An overview of hydrogen and oxygen machines distinguishes the differentiated uses of fuel cells and piston engines according to their field of application. Innovations across the entire range of mobility are analyzed as well as their diversified sources of primary energy. The applications in advance of phase on generator sets and poly-generation as well as on the real potentialities of enriched hydrogen conclude this article.
Unconventional engines have been the subject of progressive and disruptive innovations for decades, which most often result in mixed success. However, in the context of the new decarbonized energy paradigm, one of the major trends is to jointly combine electric and pneumatic engines with combustion engines. This article studies pneumatic engines, camshaftless engines, the automotive gas turbine and the promising new generation of combined thermal and electrical energy production in fixed-station installations.
Many original ideas for replacing the usual kinematics of motion transformation by connecting rod-crank of piston engines have been regularly proposed since the early 1900s: they are presented in this paper. Some of these concepts are emerging again at the beginning of the 21st century due to the new decarbonized energy paradigm. This paper mentions the renewed interest observed with opposed piston engines, free piston engines and the Wankel rotary engine.
The conversion of chemical energy into mechanical energy in a thermal machine has been carried out with an overall modest intrinsic conversion efficiency. It is therefore appropriate to favor the partial recovery of waste energy to produce additional usable energy that can be converted into hot and cold heat as well as additional mechanical energy. This makes it possible to improve the energy efficiency of the system by accepting increased complexity and cost. This paper recalls the scientific concepts that govern energy conversion, emphasizes the delicate coupling of cyclic transfers of mass and energy inherent in volumetric thermal machines, and presents technologies for recovering waste energy in combined energy production installations
In external combustion engines, no heat supply to the work fluid is produced by combustion inside the engine. The heat intakes produced by external combustion are made by thermal exchanges by the walls of cylinders or by heat exchangers. These hot gas engines have the advantage of being able to operate with all kinds of energy sources and modern technologies make it possible to improve their performance. This paper focuses on these engines which find a renewed interest as well as in the application of fatal energy recovery with the imperative need to favor the sources of de-carbon energy.
Access to a comprehensive database of articles
Rely on the ultimate technical and scientific knowledge database
Contents written and validated by leading experts to ensure reliability and expertise
Our experts committeeQuizzes, medias, tables, formulas, videos, practical paths, etc...
Enhanced reading experience
Reference articles available in English and French
Updates available in both languages
|
Single-user
1821 € excl. VAT
|
||
| Knowledge database | ||
| Number of licenses | Depending on company size | 1 |
| Languages | French and/or English | French and/or English |
| Access to enhanced reference articles | Unlimited | Unlimited |
| Access to archives | ||
| Publication updates and monitoring tools | ||
