Congrès International d'Architecture Moderne

About: Congrès International d'Architecture Moderne is a based out in . It is known for research contribution in the topics: Boundary value problem & Jet (fluid). The organization has 393 authors who have published 403 publications receiving 4104 citations.

Miniaturized active air sampling method for the analysis of tire rubber pollutants from indoor and outdoor places.

Abstract: An effective, quick and sustainable air analysis method was developed to analyse 41 volatiles and semi volatile organic compounds present in tire rubber and crumb rubber materials The proposed method, based on active sampling using a sorbent material followed by an ultrasound assisted extraction, was developed with the aim of obtaining a fast and simple procedure to determine polycyclic aromatic hydrocarbons, plasticizers, antioxidants and vulcanisation agents in air A small amount of sorbent (25 mg) was used, and the analytes were recovered in only 1 mL of solvent An experimental design was applied to study the influence of main factors such as type of sorbent and type of solvent, extraction technique (ultrasound assisted extraction and vortex extraction), extraction time, as well as the factor interactions Under optimal conditions, no breakthrough occurs in the studied interval (up to 4 m3 ) Linearity was demonstrated in a wide concentration range Accuracy of the total sampling-extraction analysis was evaluated obtaining satisfactory recoveries as well as good precision The method was successfully applied to different outdoor and indoor air environments, including a recycled rubber synthetic turf football pitch This article is protected by copyright All rights reserved

Gear Transmission Density Maximization

Abstract: Maximization of the gear transmission density presents an important task. It allows to increase the output torque within given dimensional constrains that is critical, for instance, in racing gearboxes, or to reduce size and weight of aerospace gear drives. It can also lead to reduced costs for automotive and consumer product gear trains, etc. There are several ways to increase gear drive load capacity, including advanced design, materials, and technologies. This paper presents an approach that allows optimizing gearbox kinematic arrangement and gear tooth geometry to achieve high gear transmission density. It introduces dimensionless gearbox volume functions, which can be minimized by the internal gear ratio optimization. Different gearbox arrangements are analyzed to define a minimum of the volume functions. Application of the asymmetric gear tooth profiles power density maximization is also considered.Copyright © 2011 by ASME

Stall Margin Improvement in Three-Stage Low Pressure Compressor by Use of Slot Type Casing Treatments

Abstract: The Central Institute of Aviation Motors (CIAM) has been engaged in the development of methods and technologies extending the range of stable operation for GTE axial compressors on the basis of systematic experimental and theoretical investigations of processes before and after flow disturbances for many years. The general sources of experimental data were stage models of various types. They are first supersonic stages with 0.3–0.45 hub ratio and subsonic stages with 0.75 hub ratio, as well as high-loaded stages with low aspect ratio.As a result of these investigations, a structural configuration of the casing treatment (CT) was designed to prevent local flow separation on flow passage surfaces of a compressor stage.The CT structure includes the following components:- Slotted spacer installed above the inlet rotor section;- Attached ring covering the slotted spacer.An approximate procedure for selecting the optimal CT geometric parameters and their interrelations was developed for CT designing. Using this procedure, special investigations were completed and detected the CT effects on operation of the axial compressor.These effects are:- Effect of air back and forward leakage through slots between the blade tips and the inlet rotor section;- Effect of stall deceleration in the stage flow passage;- Pulsation damping at the stage tip when flowing around the CT slotted spacer.Based on this methodology, CT prototypes were developed and tested in various single-stage and multi-stage compressors. As an example of CT advantages, we can show test results for a three-stage low-pressure compressor (LPC) designed by CIAM.The LPC in take-off conditions provides the following design parameters:- Pressure ratio: 3.4;- Corrected tip speed: 418 m/s;- Stall margin: 20% … 21% within 0.5–1.0 corrected RPM.According to experimental investigations, the use of CT results in a considerable increase in LPC stall margin without losses in other design parameters. Additionally, the results of 3D viscous flow calculation are shown for compressor performance analysis.Copyright © 2014 by ASME

Mathematical modeling of flows in wind turbines with a vertical axis

Abstract: Flow in the rotors of wind turbines with a vertical axis of the Darrieus-Savonius type and their combinations is considered within the framework of the Navier-Stokes equations, in the two-dimensional formulation. A parametric investigation of the Darrieus rotor characteristics is carried out. For all configurations the dependence of the moment and power coefficients on the specific speed of the rotor is calculated. The possibility of the Darrieus rotor self- starting from the state of rest is investigated. The effect of nonmonotonicmoment variation for the Darrieus-type rotor is studied for the specific speeds of 0.5 to 1. A combined design of the Darrieus-Savonius rotor is considered to solve the problems due to a small moment of the Darrieus rotor during the start.