Opto-mechanical design for sight windows under high loads. (5th March 2017)

• Record Type: Journal Article
• Authors: Ihracska, Balazs; Crookes, Roy James; Montalvão, Diogo; Herfatmanesh, Mohammad Reza; Peng, Zhijun; Imran, Shahid; Korakianitis, Theodosios
• Is Part Of: Materials & design. Volume 117(2017)
• Page Start: 430
• Page End: 444
• Publication Date: 2017-03-05
• Subjects: Optically-accessible reactor -- Optical engine -- Pressure vessel -- Sapphire -- Window design -- Combustion; Materials -- Periodicals; Engineering design -- Periodicals; Matériaux -- Périodiques; Conception technique -- Périodiques; Electronic journals; 620.11
• DOI: 10.1016/j.matdes.2016.12.080
• Languages: English
• ISSNs: 0264-1275

Abstract

Abstract: In this study, the design aspects of optically accessible pressure vessels are investigated via a case study of a High Pressure Combustor experimental rig. The rig was designed to take optical measurements of combustion, simulating the conditions found in internal combustion engines and turbines. Although, it is not new to equip chambers and reactors with sight windows, important aspects of design and relevant information regarding optical access is missing or are insufficiently explored or not readily accessible in the existing literature. A comprehensive review of requirements for optical access to such high-pressure, high-temperature systems has been conducted. It is shown in a readily-navigable format as function of application and precision, with data and technical correlations hitherto not found in a 'user-friendly' style. The material selection procedure is detailed and supported by a complete comparison of optical materials and relevant properties. The review revealed a significant inconsistency in mechanical properties claimed in the literature for optical materials. As a response to this, increased safety factor values are suggested as function of level of uncertainties and effects of failure, typically three to four times higher than the industrial standard. Moreover, newly developed equations are presented linking performance analysis to the design criteria. Graphical abstract: Highlights: The relevant properties of practical optical materials were collected and presented in a readily navigable format. Mechanical properties of optical materials are found to be inconsistent for elevated temperatures and for fatigue loads. In response to the unreliable material data increased safety factors are required, detailed recommendations are provided. As function of application, clear design criteria recommendations are shown. Aspects of opto-mechanical performance were described in depth and newly developed equations and relations are presented.