A SIMPLE METHOD TO DETERMINE THE DAYLIGHT FACTOR FROM THE VERTICAL DAYLIGHT FACTOR IN DIFFERENT STREET CANYON GEOMETRY

2016 ◽  
Vol 11 (2) ◽  
pp. 75-92
Author(s):  
Jorge S. Carlos

This paper investigates the main characteristics of daylight on any window in a street canyon. The sky component and the light reflected from the surroundings are described to determine the vertical daylight factor (VDF). Several street canyon types are characterized taking into account their different height/width and any level of the window is analysed. A simple calculation method uses trigonometric equations based on the sky and the geometry of the canyon. The results were previously evaluated considering different daylight procedures obtained by other studies. This study reveals that the reflectance within an urban canyon plays an important role in the amount of daylight onto any window with more relevance in a deep canyon and low sky view. The graphical presentation that result from this investigation can rapidly assist building and urban designers in an early stage design where assumptions and the lay out of the main design take place.

2021 ◽  
Vol 1 ◽  
pp. 11-20
Author(s):  
Owen Freeman Gebler ◽  
Mark Goudswaard ◽  
Ben Hicks ◽  
David Jones ◽  
Aydin Nassehi ◽  
...  

AbstractPhysical prototyping during early stage design typically represents an iterative process. Commonly, a single prototype will be used throughout the process, with its form being modified as the design evolves. If the form of the prototype is not captured as each iteration occurs understanding how specific design changes impact upon the satisfaction of requirements is challenging, particularly retrospectively.In this paper two different systems for digitising physical artefacts, structured light scanning (SLS) and photogrammetry (PG), are investigated as means for capturing iterations of physical prototypes. First, a series of test artefacts are presented and procedures for operating each system are developed. Next, artefacts are digitised using both SLS and PG and resulting models are compared against a master model of each artefact. Results indicate that both systems are able to reconstruct the majority of each artefact's geometry within 0.1mm of the master, however, overall SLS demonstrated superior performance, both in terms of completion time and model quality. Additionally, the quality of PG models was far more influenced by the effort and expertise of the user compared to SLS.


Procedia CIRP ◽  
2015 ◽  
Vol 28 ◽  
pp. 125-130 ◽  
Author(s):  
M. Colledani ◽  
L. Bolognese ◽  
D. Ceglarek ◽  
F. Franchini ◽  
C. Marine ◽  
...  

1988 ◽  
Vol 25 (04) ◽  
pp. 239-252
Author(s):  
G. Robed Lamb

Even though in 1987 there were only a dozen SWATH (smali-waterplane-area twin-hull) craft and ships afloat around the world, word of their markedly superior seakeeping performance is spreading rapidly. The number of SWATH vessels is likely to double within five years. As in many other areas of technology, the United States and Japan are the acknowledged leaders in the development and practical application of the SWATH concept. This paper reviews the characteristics of existing SWATH craft and ships from the standpoint of the stated seakeeping objective. Hull form differences between four SWATH craft and ships, including the Navy's SSP Kairnalino, are analyzed and interpreted. Important considerations for the early-stage design of a SWATH ship are discussed. Differences in the range of feasible hull form geometries for coastal areas and unrestricted ocean operations, and for low-speed versus moderately high-speed applications, are pointed out.


2021 ◽  
Author(s):  
Jonathan M. Smyth ◽  
Robert J. Miller

Abstract This paper proposes a new duty-based Smith Chart as part of an improved method of selecting the geometric topology of compressors (axial, mixed or radial) in the earliest stage of design. The method has a number of advantages over previous methods: it is based on the non-dimensional flow and the non-dimensional work, which aligns with the aerodynamic function of the compressor and is therefore more intuitive than specific speed and specific diameter. It is based on a large number of consistently designed compressor rotors which have been computationally predicted using RANS CFD. Most importantly, it provides the designer not only with a choice of topology but also with the complete meridional geometry of the compressor, its blade design and the number of blades. This fidelity of geometry at the very early stage of design allows the designer to undertake a true systems design optimization (noise, manufacturing, packaging constraints and cost). This has the major advantage of significantly reducing early stage design times and costs and allows the designer to explore completely new products more quickly.


2010 ◽  
Vol 431-432 ◽  
pp. 237-240 ◽  
Author(s):  
Peng Chen ◽  
Ping Jun Xia ◽  
Yue Dong Lang ◽  
Ying Xue Yao

In this paper, a Colored Petri Net modeling method for early stage design of virtual assembly operation is presented. The characteristics of virtual assembly system, Petri Net and Colored Petri Net are analyzed. Some previous work in Petri Net application in assembly and virtual assembly system is discussed. The theoretical aspects of Colored Petri Net are introduced mathematically. Based on the mathematical presentation and the process of fasteners assembly operation, a Colored Petri Net model is constructed for the simulation of assembly operation in virtual environment. With CPN Tools software package, the simulation for evaluating the feasibility of modeling is implemented. It is demonstrated that the modeling approach can support the early stage design of virtual assembly system.


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