Space Truss Structures: Typological Characteristics and Principal Construction Systems in Italy

1994 ◽  
Vol 9 (4) ◽  
pp. 191-200 ◽  
Author(s):  
Giuseppe Prete

In the field of civil and industrial buildings and, particularly, dealing with coverings of wide areas, space truss structures are spreading more and more. Modern tridimensional steel systems are made up to the modular aggregation of standardized structural single or multiple elements, coordinated in space in accordance with rational geometric criteria, mass produced on an industrial scale and designed for a fine and functional architecture. Concerning these structures, the paper presents basic qualitative and performance characteristics, main typologies for the applications and, lastly, some among the most significant structural systems patented by Italian production.

2021 ◽  
Author(s):  
Nicole A. Pettingill ◽  
Nikolas S. Zawodny ◽  
Christopher Thurman ◽  
Leonard V. Lopes

Author(s):  
R B Anand ◽  
L Rai ◽  
S N Singh

The effect of the turning angle on the flow and performance characteristics of long S-shaped circular diffusers (length-inlet diameter ratio, L/Di = 11:4) having an area ratio of 1.9 and centre-line length of 600 mm has been established. The experiments are carried out for three S-shaped circular diffusers having angles of turn of 15°/15°, 22.5°/22.5° and 30°/30°. Velocity, static pressure and total pressure distributions at different planes along the length of the diffusers are measured using a five-hole impact probe. The turbulence intensity distribution at the same planes is also measured using a normal hot-wire probe. The static pressure recovery coefficients for 15°/15°, 22.5°/22.5° and 30°/30° diffusers are evaluated as 0.45, 0.40 and 0.35 respectively, whereas the ideal static pressure recovery coefficient is 0.72. The low performance is attributed to the generation of secondary flows due to geometrical curvature and additional losses as a result of the high surface roughness (~0.5 mm) of the diffusers. The pressure recovery coefficient of these circular test diffusers is comparatively lower than that of an S-shaped rectangular diffuser of nearly the same area ratio, even with a larger turning angle (90°/90°), i.e. 0.53. The total pressure loss coefficient for all the diffusers is nearly the same and seems to be independent of the angle of turn. The flow distribution is more uniform at the exit for the higher angle of turn diffusers.


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