Effect of surface material properties and surface characteristics inevaporative spray cooling

1990 ◽  
Author(s):  
M. SEHMBEY ◽  
M. PAIS ◽  
L. CHOW
Keyword(s):  
Material Properties ◽  
Surface Characteristics ◽  
Spray Cooling ◽  
Surface Material ◽  
Effect Of Surface

Water Film Depth Prediction Model for Highly Textured Pavement Surface Drainage

2021 ◽  
pp. 036119812110363
Author(s):  
Alireza Pourhassan ◽  
Ahmed A. Gheni ◽  
Mohamed A. ElGawady
Keyword(s):  
Prediction Model ◽  
Water Film ◽  
Crumb Rubber ◽  
Surface Material ◽  
Textured Surfaces ◽  
Road Traffic Safety ◽  
Material Type ◽  
Chip Seal ◽  
On Chip ◽  
Effect Of Surface

Water film depth (WFD) is an important factor for road traffic safety because of its direct connection with skid resistance, hydroplaning speed, and the tendency of splash and spray. Increasing the pavement macrotexture reduces WFD. However, existing models for WFD prediction have not been developed on highly textured surfaces such as chip seal. Furthermore, the rainfall intensities used for developing most of these models were relatively low, leaving no or low WFD on chip seal surfaces. To propose a WFD prediction model suitable for highly textured surfaces and to consider the effect of surface material type, an experimental study was conducted with 154 different combinations of mean texture depth (MTD), surface material type, surface slope, drainage length, and rainfall intensity. The tests were carried out on chip seal specimens using a full-scale rainfall simulator. Test results from 1,784 WFD readings indicated that the Gallaway and PAVDRN models were not accurate for highly textured surfaces used in this study with MTD ranging from 0.05 to 0.20 in. Two experimental models were, therefore, proposed to predict the WFD; both models displayed a significantly higher correlation between the measured and predicted WFD compared with the existing models. Furthermore, the eco-friendly rubberized chip seal showed an enhanced drainage capability compared with conventional chip seal, especially in low slopes, because of the hydrophobic nature of crumb rubber versus the hydrophilic character of mineral aggregates. Accordingly, the proposed model incorporated a term to consider the effect of surface material type.

Comparisons of Surface Roughness for Precision Ground Different Brittle Materials

2009 ◽  
Vol 416 ◽  
pp. 593-597
Author(s):  
Jian Yun Shen ◽  
Xi Peng Xu
Keyword(s):  
Surface Roughness ◽  
Formation Mechanism ◽  
Material Properties ◽  
Brittle Materials ◽  
Mesh Size ◽  
Surface Characteristics ◽  
Grinding Process ◽  
Surface Formation ◽  
Surface Topographies ◽  
Engineering Materials

Brittle materials are popularly used as engineering materials for excellent properties. But the properties of brittle materials are different and special, and cause to different surface formation mechanism during the grinding process. In the study, surface roughnesses after grinding with different mesh size diamond wheels were measured. Combined with scanned surface topographies, the relation between the surface roughness and the properties of these brittle materials was discussed. It could be found that the material properties led to the different surface characteristics of brittle materials.

Sign in / Sign up

Export Citation Format

Share Document