Numerical analysis of a fin-tube plate heat exchanger with winglets

In this presented work, numerical analysis of heat transfer and flow characteristic using longitudinal vortex generators (LVGS) in fin and flat tube heat exchanger has been presented. Conjugate heat transfer 3D numerical model has been developed and successfully carried out. Rectangular winglets were set in pairs, with downstream orientation. The effects of impact angles of (20⁰ , 30⁰, and 40⁰ ) as well as tubes and winglets were placed in one row lined arrangement and air flow by forward arrangement and backward arrangement. Reynolds number is ranged from 500 to 5000. The numerical results showed that in the range of the present study, the variation of these parameters can result in the increase of heat transfer. The study focuses on the Influence of the different parameters of VGs on heat transfer and fluid flow characteristics of one row lined circular-tube banks. The characteristics of average Nu number and skin friction coefficient are studied numerically by the aid of the computational fluid dynamics (CFD) commercial code of FLUENT ANSYS 14. The results showed increasing in the heat transfer and skin friction coefficient with the increasing of Re number. It has been observed that the overall Nuav number of one circular tubes increases by 23-31% ,by 23-43% and by 23-47% with angles of (20⁰, 30°, and 40⁰) respectively, in forward arrangement and the overall Nuav number of one circular tubes increases by 23-42%, by 23-46% and 23-52%with angles of (20⁰, 30°, and 40⁰) respectively, in backward arrangement, with increasing in the overall average of skin friction coefficient. Also the results showed that the rectangular winglet pairs (RWPs) can significantly improve the heat transfer performance of the fin and-tube heat exchangers with a moderate pressure loss penalty

Avionics test bed development plan

A development plan for a proposed avionics test bed facility for the early investigation and evaluation of new concepts for the control of large space structures, orbiter attached flex body experiments, and orbiter enhancements is presented. A distributed data processing facility that utilizes the current laboratory resources for the test bed development is outlined. Future studies required for implementation, the management system for project control, and the baseline system configuration are defined. A background analysis of the specific hardware system for the preliminary baseline avionics test bed system is included

Survey of currently available high-resolution raster graphics systems

Presented are data obtained on high-resolution raster graphics engines currently available on the market. The data were obtained through survey responses received from various vendors and also from product literature. The questionnaire developed for this survey was basically a list of characteristics desired in a high performance color raster graphics system which could perform real-time aircraft simulations. Several vendors responded to the survey, with most reporting on their most advanced high-performance, high-resolution raster graphics engine

Representing older people: towards meaningful images of the user in design scenarios

Designing for older people requires the consideration of a range of difficult and sometimes highly personal design problems. Issues such as fear, loneliness, dependency, and physical decline may be difficult to observe or discuss in interviews. Pastiche scenarios and pastiche personae are techniques that employ characters to create a space for the discussion of new technological developments and as a means to explore user experience. This paper argues that the use of such characters can help to overcome restrictive notions of older people by disrupting designers' prior assumptions. In this paper, we reflect on our experiences using pastiche techniques in two separate technology design projects that sought to address the needs of older people. In the first case pastiche scenarios were developed by the designers of the system and used as discussion documents with users. In the second case, pastiche personae were used by groups of users themselves to generate scenarios which were scribed for later use by the design team. We explore how the use of fictional characters and settings can generate new ideas and undermine rhetorical devices within scenarios that attempt to fit characters to the technology, rather than vice versa. To assist in future development of pastiche techniques in designing for older people, we provide an array of fictional older characters drawn from literary and popular culture.</p

Disability and Technology

Disability and Technolog

Longitudinal analysis of student performance between host and cooperating college learners in the dental hygiene program at Northcentral Technical College in Wausau, Wisconsin

Includes bibliographical references