Mechanical Engineering and Sciences http://iptek.its.ac.id/index.php/jmes/index J ES The International Journal of Numerical Study of Temperature and Air Velocity Distribution in Oil Filling Factory Hernawan Novianto and Prabowo * Department of Mechanical Engineering, Institut Teknologi Sepuluh Nopember, Surabaya 60111, Indonesia Received: 10 June 2017, Revised:8 July 2017, Accepted: 15 August 2017 Abstract This paper describes the use of CFD modeling to analyze the thermal comfort in the oil filling factory which has an area of 3000 m 2 . The need for this analysis comes from an uncomfortable condition that is felt by the workers of the factory. A 3D simulation using FLUENT software 6.3.26 conducted to analyze the temperature and velocity distribution in the plant room. The water is assumed as an incompressible ideal gas, steady flow, turbulence models used k-ε standard, the SIMPLE algorithm and second order upwind discretisation. Analysis was conducted on existing models and propose models, whereby on a model propose, the diffuser is installed above the workers with a height of 4,2 m above the floor, the velocity of supply air diffuser is varied from 1,5 m/s, 2 m/s, and 2,5 m/s. The simulation results show that the temperature distribution in the existing conditions in the range of about 34-36 ◦ C, this value exceeds the thermal comfort standards specified by ASHRAE. The simulation results show that the proposed model better temperature distribution, where the temperature is generated in the range of ASHRAE thermal comfort criteria, ranging from 24-26 ◦ C, and the supply air velocity at the diffuser inlet of 1,5 m/s recommended for use in AHU system. For the 20 units of the diffuser with inlet velocity of 1,5 m/s, the mass flow rate that should be handled by a cooling device is 9 kg/s and require a cooling capacity of 0,128 MW. This is 58% more efficient than cooling the entire room factory. Keywords: Distribution of Temperature, Velocity Distribution, CFD modeling. 1. Introduction Planning air conditioning systems not only overcome the problem of thermal comfort but also reduces energy use is something that is needed today. The use of CFD for analyzing the temperature in the room has increased, such as apartment [1], the office [2], clinic [3], the museum [4], stadium [5], theatre [6] and the airport terminal [7]. In this study, CFD is used to analyze the temperature and air velocity distribution in the oil filling factory room in Gresik, Indonesia, Figure 1 shown layout of the plant which has an area of 3000 m 2 . The need for this analysis came from uncomfortable conditions felt by the workers of the factory. Some actions have been carried out such as adding 24 units of ventilators and 7 units of blower fan, but the room temperature is still high. Several studies conducted to investigate the thermal comfort in large buildings equipped with a cooling sys- tem. Yong wang et al. [8] studied full and stratified air conditioning design in buildings with large space. They compare and analyze the indoor comfort parameters such as temperature and air velocity, result in recommendations to use of stratified air conditioning design for large space buildings. Q. Li et al. [9] evaluate the thermal environ- ment in the room of the railway station building, they are also investigating on the temperature and air velocity, and found that the mid-height of the building is a good position for the air cooling supply and horizontal angle of 0 o supply is recommended. The above literature is about room temperature, and nothing has been said about the temperature on people’s body surface. Therefore, the present work investigates numerically the temperature distribution on worker body surface. The purpose of this research is to investigate the thermal comfort of workers if the spot cooling conducted. The influence of the air supply to the temperature and air velocity distribution on the body surface discussed. From these discussions, advice on optimizing the design of air conditioning made. The main objective is to introduce an effective way to assess and optimize the design of air conditioning. 2. Model Description 2.1. Configuration Investigated oil filling factory is located in Gresik, Indonesia, a building size of about 75m (length) x 40m (width) x 13,4m (high). The size is too complex to be analyzed, therefore line 2 shown in Figure 2 is selected for sample to be analyzed, and the model is simplified. * Email:prabowo@me.its.ac.id Phone:+628 The International Journal of Mechanical Engineering and Sciences; Vol. 1 , No. 2 (2017): 1-8