In this paper, experimental and numerical comparison of Baseboard radiator and Panel radiator are presented. Rated capacity of both radiators was 1200 kcal per hour. In the experimental section, at the same ambient temperature for both radiators, capacity and characteristic equation and temperature distribution in a room with dimensions of 2. 6 × 4 × 4 meter was obtained. The experimental results showed that a Uniform Temperature distribution occurs in the room for the Baseboard radiator, Temperature difference in vertical direction for center of the room for the Panel radiator in various capacities changes 3° C to 7° C, While for the Baseboard radiator at all capacities temperature difference was about 2 ° C. Temperature difference at height of 1. 5 m in horizontal direction from wall that the Panel radiator was installed to facing wall, changes 3° C to 6° C. While for the Baseboard radiator, this result was about 0. 5° C. To investigate the cause of the temperature distribution, numerical modeling was used. Numerical results and experimental results were close with 10% error. Temperature distribution curves At plane of symmetry room for both samples was drawn, Baseboard radiators were more uniform temperature distribution again. In the end, the velocity distribution diagram in the vertical plane of symmetry room was obtained which show that a strong circulation occurs in the room for the Baseboard radiator.

In the current research, finite element simulation and experimental tests have been used to design, manufacture, and evaluate the performance of a high-power ultrasonic circular radiator called ultrasonic airborne. The two main goals in the design are to achieve a nominal resonance frequency of 20 kHz in the longitudinal mode shape of the transducer and booster assembly and the flexural mode shape of the circular radiator plate and to remove the disturbing modes from the frequency range of the main mode shape. After designing and manufacturing the sample based on the simulation results, experimental tests consisting of a modal impact test, impedance analysis, and amplitude measurement were performed. Simulation results, including the resonance frequency and position of the node and anti-node, were compared with the experimental results. The experimental test results of the resonance frequency compared with the simulation results, indicate the accuracy of the prediction of the results of the resonance frequency with the designed nominal value (error less than 0.5%). Also, the disturbing mode shapes were at an acceptable distance from the main flexural mode shape of the radiator. Reasonable agreement is achieved between experimental vibration amplitude measurement and finite element simulation predictions (position of the node and anti-node).

Nowadays, computer simulations are becoming more and more important in performance investigation of thermal systems. In this article, radiator from a cooling system of a diesel engine of ER24PC locomotive is simulated. The radiator is composed of parallel and series arrangement of compact heat exchangers with offset strip fins. It also has two high and low temperature sections. Due to the complexity and compactness of heat transfer plates implemented in the radiator, the simulation is carried out in two steps. First, a relation for coolant-side and air -side heat transfer coefficient is correlated using computational fluid dynamics. Due to vortex shedding phenomenon in the staggered fin arrays, governing equations are solved transiently in twodimensional space. Appropriate timestep for the transient solution is chosen according to time period of vortex shedding from the surface. In the second step, using the developed computational code, the overall thermal performance of the radiator is simulated as a heat exchanger. Consequently, temperature distribution inside the radiator and its thermal performance are studied. Amount of heat released from the radiator in different flow rates and temperatures of fluid flowing out of the radiator are among the outputs of the developed code. Finally, thermal performance curve of radiator is obtained.

In This study, an experimental study has been carried out to investigate the effect of adding Al2O3, Al, and Cu nanoparticles to the base fluid (water) on enhancement of heat transfer and heat transfer coefficients in a car radiator. The experiments have been done for distilled water and 3 types of nanofluids with different concentrations (0.5, 1 and 2 vol. %) and in various operational conditions (temperature, flow rate, etc.). Thermal Conductivities of these fluids have been measured experimentally and other thermo-physical properties like density and viscosity are calculated using related models. Results depicted that addition of nanoparticles to the base fluid increases its thermal conductivity, density and viscosity, and decreases its specific heat capacity. The performance evaluation of nanofluids in a radiator system showed that will dramatically enhances the heat transfer and decreases the heat transfer area required, so it is highly recommended to use them in such systems.

Background: Airborn lead level in Tehran's radiator repair plants is six times higher than the standard level. This high percentage necessitates evaluating engineering controls and efficient ventilation system in these plants. Objective: To evaluate cost-effective ventilation enclosure made of a flexible silicone sheet that forms a tent-like structure verthe water bath that is used to leak test radiators. Methods: Through an experimental study, the samples were gathered from 10 radiators repair plants which had no technical control the effectiveness of this ventilation enclosure was evaluated by collecting short-term and time-weighted average personal samples for lead data (controlled work-station) that used the enclosure. In addition, similar Personal breathing zone samples for lead were collected at a work-station in the same facility without the enclosure (uncontrolled). Finding: Lead exposure during radiator repair at the controlled work-station was 24 µg/m3  (50% of OSHA PEL). Personal breathing zone samples taken at uncontrolled work-stations averaged 143 µg/m3 which was 7 times higher than controlled stations. Conclusion: The results demonstrated an excellent control of lead fumes using this ventilation enclosure.      

Wind is one of the factors influencing the performance of the dry cooling tower. According to research, wind will decrease the efficiency of dry cooling tower about 20%. Therefore, many studies have been done to improve the performance of dry cooling towers. Although various numerical methods and wind tunnel studies have been conducted, but the data obtained has not been properly validated and therefore requires that the appropriate field research done. To study the effect of wind on the performance of dry cooling tower, it is appropriate to model airflow around the cooling tower and the entrance of the deltas. In this research, which is the field research, air flow pattern around the tower and the deltas of Montazar ghaem plant cooling tower has been evaluated. The survey results found that the flow around the cooling tower has no separation. The sectors are positioned in front and back of the wind have the most efficiency and the least efficient sectors that are tangential to the wind. There is a vortex flow pattern in the critical deltas.

In this study, heat transfer and aerosol deposition in the under-floor and Baseboard heating systems have been investigated, numerically. The aim of this study is a comparison between these heating systems. This comparison obtains the optimal heating system with low suspended particles in the air. Computational fluid dynamic with Eulerian-Lagrangian method has been used to simulate fluid and particles flows. The velocity and temperature distribution have been obtained by solving the equations of continuity, momentum and energy. It is resulted that, the radiant heat transfer contains about 63 % and 60 % of overall heat transfer of the under-floor and Baseboard heating systems, respectively. Side walls have a same condition for deposing the particles in both of investigated heating systems, approximately. But, in floor heating system, most of the particles are deposited under the roof, while the Baseboard heating system has a more percentage of seated particles on the floor.

One of the main challenges in designing a vehicle's cooling system, particularly the radiator, is not considering the non-uniform airflow distribution in the radiator's characteristic performance graphs. In this study, a three-dimensional numerical analysis of the airflow passing through a QUIK vehicle and the effect of the cooling system's placement relative to the vehicle's grille in five different cases was conducted. The effect of non-uniform airflow distribution on related radiator parameters such as the Darcy number, particle diameter, and inertial term was examined. The results indicate that the optimal placement range of the vehicle's cooling system for appropriate cooling performance is very limited. Additionally, non-uniform air velocity distribution plays a significant role in the radiator pressure drop. The inertial term is more significant in non-uniform flow conditions. For larger Forchheimer numbers, the change in radiator pressure drop for uniform compared to non-uniform flow distributions is about 22%.

radiators are common devices for heating of home and office spaces and have a close relationship with the energy sector. In a radiator, heat transfer is increased with increasing of air flow rate along heated surface as well as temperature difference between bulk air and heated surface. First, in order to find the optimum design of an Aluminum radiator numerical analysis of free convection heat transfer using commercial software Fluent was performed and then to thermal evaluation of it the Iranian national standard 4022 which is accordance with international standard ISO 3148 is used as reference experiment. In according to the standard, the test room includes a double room: interior and exterior chamber.The radiator is placed inside the chamber and the exterior chamber is cooled using cooled air. Here, three sets of experimental test are performed at different average of inlet and outlet water temperature of 80 ± 5, 65 ± 5 and 50 ± 5 °C. The average temperature of the interior testing room is controlled by 20 thermocouples mounted in the test room to be maintained in the range of 19 to 21 °C.Experimental results of the radiator heat rate were compared with numerical analysis and good consistency between results was found.