Faculty Publications
Permanent URI for this communityhttps://idr.nitk.ac.in/handle/123456789/18736
Publications by NITK Faculty
Browse
Search Results
Item CFD and experimental optimization of formula SAE race car cooling air duct(SAE International, 2013) Kamath, S.R.; Prajwal Kumar, M.P.; Shashank, S.N.; Damodaran, V.; Anand, S.R.; Kulkarni, P.Engine overheating problems have been the major cause for vehicle breakdown during FSAE endurance runs. Therefore, it is crucial to study the cooling performance, which is affected by the air flow through the side-pod. CFD is used as a tool for this study and simulation based on the complete race car 3D model (NITK Racing 2012 formula student race car - NR XII) is carried out for different cases. Further, Wind Tunnel Experiment is carried out to validate these results. The results obtained for different cases are analyzed to decide the best configuration of the cooling duct. CFD analysis helped in calculating the mass flow rate through the radiator at various velocities. Pressure distribution and velocity distribution were also obtained along the length of the side-pod for different velocities of the car. Area of flow separation and turbulence is visualized and thus smooth airflow into the radiator core area is ensured. The amount of drag force generated due to the side-pod geometry and radiator configuration is also measured. This significantly increased the heat rejection and reduced drag. Copyright © 2013 SAE International.Item Effectiveness of SIP messages on SIP server(2013) Bansal, A.; Kulkarni, P.; Pais, A.R.Voice over Internet Protocol (Voice over IP, VoIP) is one of a family of communication protocols, and transmission technologies. It is used for delivery of voice communications and multimedia sessions over Internet Protocol (IP) networks. Session Initiation Protocol (SIP) is a signaling protocol, widely used for controlling multimedia communication sessions such as voice and video calls over Internet Protocol (IP). There are several DoS attacks by which we can disturb SIP server. In this paper, more importance has been given to DoS attack by flooding of different SIP-messages. A little work is done to analyze the performance of SIP server and quality of ongoing VoIP calls under DoS attacks. We show the utilization of CPU and memory during the multiple simultaneous calls. We have done our study using a customized analysis tool that has the ability to synthesize and launch flooding of different SIP messages. We define the performance metrics to measure the quality of VoIP calls under DoS attack. We have developed some programs and integrated them in a real SIP test bed environment to measure the performance of SIP server and quality of VoIP calls under DoS attack. Our measurements show that a standard SIP server can be easily overloaded by simple call requests. It also shows that simple call request can degrade quality of ongoing calls. © 2013 IEEE.