The Venturi flow meter offers a range of measurement options for liquids, gas, steam, and slurries in piped systems. The main criteria for assessing Venturi performance include permanent pressure loss, discharge coefficient, relative pressure loss coefficient, and measurement accuracy. However, the extended length of Venturis, relative to other flow rate measuring instruments, can present limitations in some applications. Furthermore, the manufacturing of shorter Venturis requires less material and energy. This study addresses the challenge by developing shorter Venturi meters that adhere to established performance standards. Previous studies show that cone angles, the ratio of throat diameter to inlet diameter (β-ratio), and the throat length impact the performance of a Venturi. The scope of this research considers single-phase, incompressible and isothermal flows. The investigation focuses on the effect of cone angles for flows with Reynolds numbers ranging from 5000 to 10,000,000. Two axisymmetric Venturis, with a β-ratio of 0.7, were designed and evaluated against an ISO-5167 classical Venturi with the same β-ratio. Despite the ISO-5167 Venturi outperforming the others across the key criteria, a Venturi designed with a 40-degree convergent cone angle and a 10-degree divergent cone angle was 24.9 % shorter than the classical design and demonstrated similar performance to the ISO-5167 Venturi across Reynolds numbers from 100,000 to 10,000,000.

To optimize a vertical flash tank separator, the characteristics of the flow entering the separator are required to be known. A flash tank separator improves the performance of a refrigeration cycle by separating the liquid from liquid-gas flow and providing the evaporator with only liquid refrigerant. This technique improves the effective area and enhances the heat transfer coefficient in the evaporator. This paper investigates the influence of the inlet operating conditions to an expansion device, on the adiabatic two-phase flow development in a horizontal pipe downstream from the expansion device. This work also compares three dimensional numerical simulations and experimental observations for the two-phase flow development after the expansion device in the horizontal pipe. A general trend of the two-phase flow after the expansion device was gradually developed and the expansion length was identified at less than 200 mm from the inlet. The two-phase flow behaviour was recorded using a digital camera recording the flow behaviour at the upstream and downstream of the horizontal tube. The results revealed that an increase of the mass flow rate causes an increase in the void fraction and a reduction in the slip ratio in the developed region. The simulations underestimate the expansion length and the mean difference between the experimental data and the numerical results is 8 %.

The broad aim of this research is to quantify the effectiveness of fences made of metal mesh around buildings in mitigating risks associated with firebrand showers created in wildland fires. This paper aims to (1) quantify the effectiveness of a mesh complying with Australian Standard 3959:2018 against firebrand showers and (2) identify behaviors of firebrands interacting with the mesh. The study was conducted using Red Gum and Cypress Pinewood firebrands inside a wind tunnel at 40 km/h with and without a mesh present for a total of 50 experiments. Two types of effectiveness were defined using the number of holes and their area burnt by the firebrand. The results show the mesh was highly effective against both large and small firebrands except for some long needle shape firebrands. The results are aligned with AS 3959:2018 and show an effectiveness ratio of the mesh in the range 93.2–98.8% for Red Gum and Cypress Pine firebrands at a wind speed of 40 km/h. It was documented that firebrands in interaction with the mesh show one or a combination of eight different mechanisms: passing, stopping, splitting, shattering, pausing, bouncing, slipping and wandering.

A common technique for producing large-scale hollow plastic items is rotomoulding. Rotation speed, mould design, and temperature management significantly affect the quality of finished products. The growing demand may cause the rotomoulding industry to reach a peak soon. Few studies have been applied in the industrial sector. Meanwhile, the lack of sufficient research on the phase transition from the heat source for the rotomoulding procedure led to a great research gap in this field. Although, their conclusions contribute significantly to the topic but cannot be considered accurate in the analysis. Proper temperature variations in both the heating and cooling phases impact the final product quality. Moreover, if the required temperature is not achieved it may result in raw material ( HDPE, LLDPE) loss. To produce the necessary amount of hot air by convection, this review article focuses on the use of ducts as the medium for hot air circulation to the mould, ducting model analysis, and mould model adjustments. Additionally, insulation has been discussed concerning sustainable heat, which could help the industry to better comprehend the procedure.