Liquidus and Gaseous Line in Phase Diagram

This paper describes that negative pair-interaction energy averaged over all particles and its density dependence gives van der Waals' equation of state through mean-field modeling and that liquidus and gaseous line for vapor-liquid phase are rigorously calculated from the equation of state, so that latent heat of vaporization and vapor pressure are obtained. Phase diagram is constructed from these lines and it is shown that the critical temperature depends not only on the size of molecule and the averaged magnitude of interaction energy but also on the mass of molecule. As a property of such system Kamerlingh-Onnes' constant is obtained

SMALL HIGH-PRESSURE CHAMBER SHOCK TUBE

ABSTRACT The unsteady supersonic jet formed by the shock tube with small high-pressure section was used as a simple alternative system of pulsed laser ablation. The dynamic of the supersonic jet impinging upon a flat plate are discussed by comparing experimental and calculated results. The experiment and numerical calculation were carried out by schlieren method and by solving the axisymmetric two-dimensional compressible Navier-Stokes equations, respectively. The main parameters are distance between the open end of the shock tube and the flat plate, L/D, and the pressure ratio of the shock tube, P h /P b . Where, L, D, P h and P b are the distance between the open end of the shock tube and the flat plate, the diameter of the shock tube, pressure of the high and low section of the shock tube, respectively. Collision between the shock wave reflected at the flat plate and the head of supersonic jet takes place. Computational results well predict the experimental dynamic behavior of the shock wave and the supersonic jet. Marked increase in the static pressure on the flat plate under high P h /P b and short L/D is observed due to interaction between the shock wave and the unsteady jet flow

Fluid flow and infrared image analyses on endwall fitted with short rectangular plate fin

An experimental investigation is carried out to study fluid flow and heat transfer characteristics on the endwall fitted with arrays (7×7) of short rectangular plate fins of different pattern (co-angular and zigzag) for different pitch ratio. Experiments were conducted in a rectangular duct of 50 mm height for an air flow of Reynolds number ranged from 18750 to 62500 based on the equivalent diameter and air velocity of the duct. Infrared image analysis technique was employed to make clear the characteristics of local heat transfer coefficients on fin base, endwall and overall surface. Flow pattern around the short rectangular plates were visualized by inducing fluorescent dye in a water channel and longitudinal vortices were observed. Increasing the distance between plates in flow direction causes heat transfer enhancement for co-angular pattern, while decreasing the distance causes heat transfer enhancement for zigzag pattern. Zigzag pattern with pitch ratio 2 is found to be more effective in heat transfer enhancement than any other cases investigated