Entropy generation for natural convection by heated partitions in a cavity

Entropy generation for natural convection in a partitioned cavity, with adiabatic horizontal and isothermally cooled vertical walls, is studied numerically by both a FORTRAN code and the commercially available CFD-ACE software. Effects of the Rayleigh number, the position of the heated partition, and the dimensionless temperature difference on the local and average entropy generation rate are investigated. Proper scale analysis of the problem showed that, while fluid friction term has nearly no contribution to entropy production, the heat transfer irreversibility increases monotonically with the Nusselt number and the dimensionless temperature difference

Scaling effects for flow in micro-channels: Variable property, viscous heating, velocity slip, and temperature jump

This paper reports closed form solutions, based on perturbation techniques, for fully developed, both hydrodynamically and thermally, slip-flow forced convection in both parallel plate and circular microchannels subject to isothermal wall boundary condition. Scaling effects, including variable property, viscous dissipation, velocity slip, and temperature jump are studied in detail. The results are not only applicable to gaseous flow in the slip-flow regime but also can be used for no-slip liquid flow in microchannels

Effects of thermal boundary condition, fin size, spacing, tip clearance, and material on pressure drop, heat transfer, and entropy generation optimization for forced convection from a variable-height shrouded fin array

Fully developed forced convection through a variable-height shrouded fin array is studied numerically. Two different base thermal boundary conditions are considered being isothermal and isoflux heating. In either case, the shroud is assumed to be adiabatic. Following the application of two separate thermal energy equations, the conjugate heat transfer problem is solved. Different fin material, spacing, height, tip clearance, and size are examined. Considering these effects, pressure drop, heat transfer, and entropy generation aspect of the problem are studied in detail

Experimental Application of Extended Kalman Filtering for Sensor Validation

A sensor failure detection and identification scheme for a closed loop nonlinear system is described in this paper. Detection and identification tasks are performed by estimating parameters directly related to potential failures. An extended Kalman filter is used to estimate the fault-related parameters, while a decision algorithm based on threshold logic processes the parameter estimates to detect possible failures. For a realistic evaluation of its performance, the detection scheme has been implemented on an inverted pendulum controlled by real-time control software. The failure detection and identification scheme is tested by applying different types of failures on the sensors of the inverted pendulum. Experimental results are presented to validate the effectiveness of the approach

The soils of Iran /

"Study conducted (1955-61) as a joint project with the Soil Department of Irrigation Bongah of the Ministry of Agriculture, the Plan Organization, and the Food and Agriculture Organization of the United Nations."Bibliography: p. 283-285