A flow is called hypersonic if the Mach number is greater than 5. This means that the flow speed is more than five times the speed of sound. In air at room temperature, the speed of sound is around 340 m/s, so a Mach 5 flow would have a flow speed of 1.7 km/s or just over 6,000 km/h. When a rocket launches a satellite into earth orbit, when a probe enters the atmosphere of another planet or when an aircraft is propelled by a supersonic combustion ramjet engine (a scramjet), hypersonic flows are encountered. Hypersonics – from Shock Waves to Scramjets introduces the basic concepts associated with flight at speeds greater than Mach 5 and takes students to the stage where they can analyse the performance of a scramjet engine that might be used in a future access-to-space system.
An excellent online course offered by edX: how it works
edX courses consist of weekly learning sequences. Each learning sequence is composed of short videos interspersed with interactive learning exercises, where students can immediately practise the concepts from the videos. The courses often include tutorial videos that are similar to small on-campus discussion groups, an online textbook, and an online discussion forum where students can post and review questions and comments to each other and teaching assistants. Where applicable, online laboratories are incorporated into the course.
edX offers certificates of successful completion and some courses are credit-eligible. Whether or not a college or university offers credit for an online course is within the sole discretion of the school. edX offers a variety of ways to take courses, including verified courses where students have the option to audit the course (no cost) or to work toward an edX Verified Certificate (fees vary by course). edX also offers XSeries Certificates for completion of a bundled set of two to seven verified courses in a single subject (cost varies depending on the courses).
An edX learning programme under Other Experiences