Computational Fluid Dynamics
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Reliability Design of Mechanical Systems Such As Compressor Subjected to Repetitive Stresses †
metals Article Reliability Design of Mechanical Systems Such as Compressor Subjected to Repetitive Stresses † Seongwoo Woo 1,* and Dennis L. O’Neal 2 1 Department of Mechanical Engineering, College of Electrical and Mechanical Engineering, Addis Ababa Science and Technology University, Addis Ababa P.O. Box 16417, Ethiopia 2 Department of Mechanical Engineering, School of Engineering and Computer Science, Baylor University, Waco, TX 76798-7356, USA; [email protected] * Correspondence: [email protected]; Tel.: +251-90-047-6711 † Presented at the First International Electronic Conference on Metallurgy and Metals (IEC2M 2021). Abstract: This study demonstrates the use of parametric accelerated life testing (ALT) as a way to recognize design defects in mechanical products in creating a reliable quantitative (RQ) specification. It covers: (1) a system BX lifetime that X% of a product population fails, created on the parametric ALT scheme, (2) fatigue and redesign, (3) adapted ALTs with design alternations, and (4) an evaluation of whether the system design(s) acquires the objective BX lifetime. A life-stress model and a sample size formulation, therefore, are suggested. A refrigerator compressor is used to demonstrate this method. Compressors subjected to repetitive impact loading were failing in the field. To analyze the pressure loading of the compressor and carry out parametric ALT, a mass/energy balance on the vapor-compression cycle was examined. At the first ALT, the compressor failed due to a cracked or Citation: Woo, S.; O’Neal, D.L. fractured suction reed valve made of Sandvik 20C carbon steel (1 wt% C, 0.25 wt% Si, 0.45 wt% Mn). -
Technical Committee E55 Manufacture of Pharmaceutical and Biopharmaceutical Products
Technical Committee E55 Manufacture of Pharmaceutical and Biopharmaceutical Products www.astm.org © ASTM International What is ASTM International? ASTM International 118 year-old international not-for-profit organization that develops consensus standards – including test methods Participation open to all - 32,000 technical experts from across the globe ASTM’s Objectives Promote public health and safety Contribute to the reliability of materials, products, systems and services 6,788 ASTM standards Facilitate national, regional, and international commerce have been adopted, used as a reference, ASTM Standards or used as the basis Known for high technical quality of national standards outside the USA Over 12,500 ASTM standards for more than 100 industry sectors Over 5,000 ASTM standards used in regulation or adopted as national standards around the world in at least 75 countries © ASTM International Role of Standards in Global Regulatory Frameworks Legal basis for the use of Standards Standards are voluntary until referenced in regulation or contracts USA Use of Standards described by FDA Other regions ASTM International Standards are cited in many laws and regulations around the world To date, E55 Pharmaceutical Standards have not been cited in regulation What are the characteristics of Standards Development Organizations (SDOs)? SDOs differ in organization and processes used to develop Standards ASTM International is a voluntary consensus standards organization “A voluntary consensus standards body is defined by the following -
Heat Transfer in Flat-Plate Solar Air-Heating Collectors
Advanced Computational Methods in Heat Transfer VI, C.A. Brebbia & B. Sunden (Editors) © 2000 WIT Press, www.witpress.com, ISBN 1-85312-818-X Heat transfer in flat-plate solar air-heating collectors Y. Nassar & E. Sergievsky Abstract All energy systems involve processes of heat transfer. Solar energy is obviously a field where heat transfer plays crucial role. Solar collector represents a heat exchanger, in which receive solar radiation, transform it to heat and transfer this heat to the working fluid in the collector's channel The radiation and convection heat transfer processes inside the collectors depend on the temperatures of the collector components and on the hydrodynamic characteristics of the working fluid. Economically, solar energy systems are at best marginal in most cases. In order to realize the potential of solar energy, a combination of better design and performance and of environmental considerations would be necessary. This paper describes the thermal behavior of several types of flat-plate solar air-heating collectors. 1 Introduction Nowadays the problem of utilization of solar energy is very important. By economic estimations, for the regions of annual incident solar radiation not less than 4300 MJ/m^ pear a year (i.e. lower 60 latitude), it will be possible to cover - by using an effective flat-plate solar collector- up to 25% energy demand in hot water supply systems and up to 75% in space heating systems. Solar collector is the main element of any thermal solar system. Besides of large number of scientific publications, on the problem of solar energy utilization, for today there is no common satisfactory technique to evaluate the thermal behaviors of solar systems, especially the local characteristics of the solar collector. -
Ashrae Ashrae Asme Astm
CHAPTER 16 REFERENCED STANDARDS This chapter lists the standards that are referenced in various sections of this document. The standards are listed herein by the promulgating agency of the standard, the standard identification, the effective date and title, and the section or sections of this document that reference the standard. The application of the referenced standards shall be as specified in Section 102.4 of the Florida Building Code, Building. American Society of Civil Engineers ASCE/SEI Structural Engineering Institute 1801 Alexander Bell Drive Reston, VA 20191-4400 Standard Referenced reference in code number Title section number 7—10 Minimum Design Loads for Buildings and Other Structures with Supplement No. 1 . 301.1.4.1, 403.4, 403.9, 708.1.1, 807.5 41—13 Seismic Evaluation and Retrofit of Existing Buildings . 301.1.4, 301.1.4.1, Table 301.1.4.1 301.1.4.2, Table 301.1.4.2, 402.4, Table 402.4, 403.4, 404.2.1, Table 404.2.1, 404.2.3, 407.4 ASHRAE ASHRAE 1791 Tullie Circle NE Atlanta, GA 30329 Standard Referenced reference in code number Title section number 62.1—2013 Ventilation for Acceptable Indoor Air Quality . .809.2 American Society of Mechanical Engineers ASME Two Park Avenue New York, NY 10016 Standard Referenced reference in code number Title section number ASME A17.1/ CSA B44—2013 Safety Code for Elevators and Escalators . 410.8.2, 705.1.2, 902.1.2 A17.3—2008 Safety Code for Existing Elevators and Escalators . 902.1.2 A18.1—2008 Safety Standard for Platform Lifts and Stairway Chair Lifts. -
Deep Foundations Under Static Axial Compressive Load1
Designation: D 1143/D 1143M – 07 Standard Test Methods for Deep Foundations Under Static Axial Compressive Load1 This standard is issued under the fixed designation D 1143/D 1143M; the number immediately following the designation indicates the year of original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A superscript epsilon (e) indicates an editorial change since the last revision or reapproval. This standard has been approved for use by agencies of the Department of Defense. 1. Scope* 1.6 A qualified engineer shall design and approve all load- 1.1 The test methods described in this standard measure the ing apparatus, loaded members, support frames, and test axial deflection of a vertical or inclined deep foundation when procedures. The text of this standard references notes and loaded in static axial compression. These methods apply to all footnotes which provide explanatory material. These notes and deep foundations, referred to herein as piles, that function in a footnotes (excluding those in tables and figures) shall not be manner similar to driven piles or castinplace piles, regardless considered as requirements of the standard. This standard also of their method of installation, and may be used for testing includes illustrations and appendices intended only for ex- single piles or pile groups. The test results may not represent planatory or advisory use. the long-term performance of a deep foundation. 1.7 The values stated in either SI units or inch-pound units 1.2 This standard provides minimum requirements for test- are to be regarded separately as standard. -
Heat Transfer (Heat and Thermodynamics)
Heat Transfer (Heat and Thermodynamics) Wasif Zia, Sohaib Shamim and Muhammad Sabieh Anwar LUMS School of Science and Engineering August 7, 2011 If you put one end of a spoon on the stove and wait for a while, your nger tips start feeling the burn. So how do you explain this simple observation in terms of physics? Heat is generally considered to be thermal energy in transit, owing between two objects that are kept at di erent temperatures. Thermodynamics is mainly con- cerned with objects in a state of equilibrium, while the subject of heat transfer probes matter in a state of disequilibrium. Heat transfer is a beautiful and astound- ingly rich subject. For example, heat transfer is inextricably linked with atomic and molecular vibrations; marrying thermal physics with solid state physics|the study of the structure of matter. We all know that owing matter (such as air) in contact with a heated object can help `carry the heat away'. The motion of the uid, its turbulence, the ow pattern and the shape, size and surface of the object can have a pronounced e ect on how heat is transferred. These heat ow mechanisms are also an essential part of our ventilation and air conditioning mechanisms, adding comfort to our lives. Importantly, without heat exchange in power plants it is impossible to think of any power generation, without heat transfer the internal combustion engine could not drive our automobiles and without it, we would not be able to use our computer for long and do lengthy experiments (like this one!), without overheating and frying our electronics. -
(CFD) Modelling and Application for Sterilization of Foods: a Review
processes Review Computational Fluid Dynamics (CFD) Modelling and Application for Sterilization of Foods: A Review Hyeon Woo Park and Won Byong Yoon * ID Department of Food Science and Biotechnology, College of Agricultural and Life Science, Kangwon National University, Chuncheon 24341, Korea; [email protected] * Correspondence: [email protected]; Tel.: +82-33-250-6459 Received: 30 March 2018; Accepted: 23 May 2018; Published: 24 May 2018 Abstract: Computational fluid dynamics (CFD) is a powerful tool to model fluid flow motions for momentum, mass and energy transfer. CFD has been widely used to simulate the flow pattern and temperature distribution during the thermal processing of foods. This paper discusses the background of the thermal processing of food, and the fundamentals in developing CFD models. The constitution of simulation models is provided to enable the design of effective and efficient CFD modeling. An overview of the current CFD modeling studies of thermal processing in solid, liquid, and liquid-solid mixtures is also provided. Some limitations and unrealistic assumptions faced by CFD modelers are also discussed. Keywords: computational fluid dynamics; CFD; thermal processing; sterilization; computer simulation 1. Introduction In the food industry, thermal processing, including sterilization and pasteurization, is defined as the process by which there is the application of heat to a food product in a container, in an effort to guarantee food safety, and extend the shelf-life of processed foods [1]. Thermal processing is the most widely used preservation technology to safely produce long shelf-lives in many kinds of food, such as fruits, vegetables, milk, fish, meat and poultry, which would otherwise be quite perishable. -
Testing Water Resistance of Coatings in 100 % Relative Humidity1
Designation: D 2247 – 02 Standard Practice for Testing Water Resistance of Coatings in 100 % Relative Humidity1 This standard is issued under the fixed designation D 2247; the number immediately following the designation indicates the year of original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A superscript epsilon (e) indicates an editorial change since the last revision or reapproval. This standard has been approved for use by agencies of the Department of Defense. 1. Scope Using Water Immersion2 4 1.1 This practice covers the basic principles and operating D 1193 Specification for Reagent Water procedures for testing water resistance of coatings by exposing D 1654 Test Method for Evaluation of Painted or Coated 2 coated specimens in an atmosphere maintained at 100 % Specimens Subjected to Corrosive Environment relative humidity so that condensation forms on the test D 1730 Practices for Preparation of Aluminum and 5 specimens. Aluminum-Alloy Surfaces for Painting 1.2 This practice is limited to the methods of obtaining, D 1735 Practice for Testing Water Resistance of Coatings 2 measuring, and controlling the conditions and procedures of Using Water Fog Apparatus tests conducted in 100 % relative humidity. It does not specify D 2616 Test Method for Evaluation of Visual Color Differ- 2 specimen preparation, specific test conditions, or evaluation of ence With a Gray Scale results. D 3359 Test Methods for Measuring Adhesion by Tape Test2 NOTE 1—Alternative practices for testing the water resistance of D 3363 Test Method for Film Hardness by Pencil Test2 coatings include Practices D 870, D 1735, and D 4585. -
Evaluating Thermal Insulation Materials for Use in Solar Collectors1
Designation: E861 − 13 Standard Practice for Evaluating Thermal Insulation Materials for Use in Solar Collectors1 This standard is issued under the fixed designation E861; the number immediately following the designation indicates the year of original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A superscript epsilon (´) indicates an editorial change since the last revision or reapproval. 1. Scope C177 Test Method for Steady-State Heat Flux Measure- 1.1 This practice sets forth a testing methodology for ments and Thermal Transmission Properties by Means of evaluating the properties of thermal insulation materials to be the Guarded-Hot-Plate Apparatus used in solar collectors with concentration ratios of less than C209 Test Methods for Cellulosic Fiber Insulating Board 10. Tests are given herein to evaluate the pH, surface burning C356 Test Method for Linear Shrinkage of Preformed High- characteristics, moisture adsorption, water absorption, thermal Temperature Thermal Insulation Subjected to Soaking resistance, linear shrinkage (or expansion), hot surface Heat performance, and accelerated aging. This practice provides a C411 Test Method for Hot-Surface Performance of High- test for surface burning characteristics but does not provide a Temperature Thermal Insulation methodology for determining combustibility performance of C518 Test Method for Steady-State Thermal Transmission thermal insulation materials. Properties by Means of the Heat Flow Meter Apparatus C553 Specification for Mineral Fiber Blanket Thermal Insu- 1.2 The tests shall apply to blanket, rigid board, loose-fill, lation for Commercial and Industrial Applications and foam thermal insulation materials used in solar collectors. -
Recent Developments in Heat Transfer Fluids Used for Solar
enewa f R bl o e ls E a n t e n r e g Journal of y m a a n d d n u A Srivastva et al., J Fundam Renewable Energy Appl 2015, 5:6 F p f p Fundamentals of Renewable Energy o l i l ISSN: 2090-4541c a a n t r i DOI: 10.4172/2090-4541.1000189 o u n o s J and Applications Review Article Open Access Recent Developments in Heat Transfer Fluids Used for Solar Thermal Energy Applications Umish Srivastva1*, RK Malhotra2 and SC Kaushik3 1Indian Oil Corporation Limited, RandD Centre, Faridabad, Haryana, India 2MREI, Faridabad, Haryana, India 3Indian Institute of Technology Delhi, New Delhi, India Abstract Solar thermal collectors are emerging as a prime mode of harnessing the solar radiations for generation of alternate energy. Heat transfer fluids (HTFs) are employed for transferring and utilizing the solar heat collected via solar thermal energy collectors. Solar thermal collectors are commonly categorized into low temperature collectors, medium temperature collectors and high temperature collectors. Low temperature solar collectors use phase changing refrigerants and water as heat transfer fluids. Degrading water quality in certain geographic locations and high freezing point is hampering its suitability and hence use of water-glycol mixtures as well as water-based nano fluids are gaining momentum in low temperature solar collector applications. Hydrocarbons like propane, pentane and butane are also used as refrigerants in many cases. HTFs used in medium temperature solar collectors include water, water- glycol mixtures – the emerging “green glycol” i.e., trimethylene glycol and also a whole range of naturally occurring hydrocarbon oils in various compositions such as aromatic oils, naphthenic oils and paraffinic oils in their increasing order of operating temperatures. -
Characterizing the Shearing Stresses Within the CDC Biofilm Reactor
microorganisms Article Characterizing the Shearing Stresses within the CDC Biofilm Reactor Using Computational Fluid Dynamics Erick Johnson 1,2, Theodore Petersen 1 and Darla M. Goeres 2,* 1 Department Mechanical Engineering, Montana State University, Bozeman, MT 59717, USA; [email protected] (E.J.); [email protected] (T.P.) 2 Center for Biofilm Engineering, Montana State University, Bozeman, MT 59717, USA * Correspondence: [email protected]; Tel.: +1-406-994-2440 Abstract: Shearing stresses are known to be a critical factor impacting the growth and physiology of biofilms, but the underlying fluid dynamics within biofilm reactors are rarely well characterized and not always considered when a researcher decides which biofilm reactor to use. The CDC biofilm reactor is referenced in validated Standard Test Methods and US EPA guidance documents. The driving fluid dynamics within the CDC biofilm reactor were investigated using computational fluid dynamics. An unsteady, three-dimensional model of the CDC reactor was simulated at a rotation rate of 125 RPM. The reactor showed turbulent structures, with shear stresses averaging near 0.365 ± 0.074 Pa across all 24 coupons. The pressure variation on the coupon surfaces was found to be larger, with a continuous 2–3 Pa amplitude, coinciding with the baffle passage. Computational fluid dynamics was shown to be a powerful tool for defining key fluid dynamic parameters at a high fidelity within the CDC biofilm reactor. The consistency of the shear stresses and pressures and the unsteadiness of the flow within the CDC reactor may help explain its reproducibility in laboratory studies. The computational model will enable researchers to make an informed decision whether the Citation: Johnson, E.; Petersen, T.; fluid dynamics present in the CDC biofilm reactor are appropriate for their research. -
A Non-Ventilated Solar Façade Concept Based on Selective and Transparent Insulation Material Integration: an Experimental Study
energies Article A Non-Ventilated Solar Façade Concept Based on Selective and Transparent Insulation Material Integration: An Experimental Study Miroslav Cekonˇ * and Richard Slávik Faculty of Civil Engineering, Brno University of Technology, AdMaS Centre, Brno 602 00, Czech Republic; [email protected] * Correspondence: [email protected] Received: 12 April 2017; Accepted: 8 June 2017; Published: 15 June 2017 Abstract: A new solar façade concept based on transparent insulation and a selective absorber is proposed, tested and compared with conventional insulation and a non-selective type of absorber, respectively. The presented study focuses on an experimental non-ventilated solar type of façade exposed to solar radiation both in the laboratory and in outdoor tests. Due to the high solar absorbance level of the façade, high- and low-emissivity contributions were primarily analysed. All of the implemented materials were contrasted from the thermal and optical point of view. An analysis was made of both thermodynamic and steady state procedures affecting the proposed solar façade concept. Experimental full scale tests on real building components were additionally involved during summer monitoring. An indicator of the temperature response generated by solar radiation exposure demonstrates the outdoor performance of the façade is closely related to overheating phenomena. From the thermal point of view, the proposed transparent insulation and selective absorber concept corresponds to the performance of conventional thermal insulation of identical material thickness; however, the non-selective prototype only provides 50% thermal performance. The results of the solar-based experiments show that with a small-scale experimental prototype, approximately no significant difference is measured when compared with a non-selective absorber type.