An approximate analytical model was developed to estimate scalar ̄ux footprint in thermally strati®ed atmospheric surface layer ̄ows. The proposed model was based on a combination of Lagrangian stochastic dispersion model results and dimensional analysis. The main advantage of this model is its ability to analytically relate atmospheric stability, measurement height, and surface roughness length...

The Stirling engine, in comparison to other classical engines, is an external enclosed heat engine cycle with extraordinary theoretical efficiency and minimal emissions. However, when combined a minor source, the productivity of suffers. Thus, this study emphasizes research on improving performance using transfer. A simulation was done CFD analysis ANSYS Fluent enhance transfer different types ...

This work is a preliminary study which focused on subjective improvements of vehicle interior noise by using active noise control techniques. A local active noise control system has been mounted inside a room in order to reduce synthesized and real engine noise in the area around the headrest of a typical car seat. Recordings before and after cancellation have been made using a Head Acoustics m...

Wind erosion in agricultural soils is dependent, in part, on the aerodynamic roughness length (z0) produced by tillage ridges. Although previous studies have related z0 to ridge characteristics (ridge height (RH) and spacing (RS)), these relationships have not been tested for tillage ridges observed in the North African agricultural fields. In these regions, due to climate and soil conditions, ...

Degradation of compressors is a common concern for operators gas turbine engines (GTEs). Surface roughness, due to erosion or fouling, considered one the major factors degradation phenomenon in that can negatively affect designed pressure rise, efficiency, and, therefore, engine aero/thermodynamic performance. The understanding aerodynamic implications varying blade surface roughness plays sign...

Silver nanoparticle-decorated graphene nanocomposites were synthesized by a facile chemical reduction approach with the assistance of supercritical CO2 (ScCO2). The silver nanoparticles with diameters of 2-16 nm are uniformly distributed and firmly anchored on graphene nanosheets. The tribological properties of the as-synthesized nanocomposites as lubricant additives in engine oil were investig...

Most land surface models require information on aerodynamic roughness length and its temporal and spatial variability. This research presents a practical approach for determining the aerodynamic roughness length at fine temporal and spatial resolution over the landscape by combining remote sensing and ground measurements. The basic framework of Raupach, with the bulk surface parameters redefine...