CFM International has completed the second phase of testing of the Leap-X core demonstrator known as eCore 1, meaning all three major elements of the first core-the turbine, the combustor and the compressor-have undergone evaluation. The results, according to Leap program director Ron Klapproth, have matched or exceeded all the company's early projections, leaving the program on schedule for certification in late 2014.
“We're very pleased with the results,” said Klapproth, who explained that the company first tests each of the components separately to evaluate different design concepts and choose the configuration to use in the core. “When we get to the point of running the core we have a pretty good idea of how we think [it] should perform. The fact that we're getting back results that are very much in line with what we expected says that whole process is working well.”
In some cases, said Klapproth, the results have proved better than originally expected; overall, however, “We're right where we expected to be,” he said. By the end of the second phase of testing, the core accumulated more than 150 test hours. On some days it ran for as long as 10 hours. “That tells you that the vehicle wants to run, so that just makes the whole testing experience go really well,” said Klapproth.
Of course, the test program remains in its early stages, as CFM prepares to build the second of three core demonstrators. Engineers have removed the first test vehicle from its test cell, and have taken it apart to inspect the condition of the hardware. Hardware for the second core, eCore 2, has begun to arrive, as the company prepares for the instrumentation cycle. “These cores have a tremendous amount of instrumentation on them,” said Klapproth. “A lot of times it turns out that instrumentation cycle is the longest part of the build cycle.”
The second core demonstrator will include a full 10-stage compressor and two-stage high-pressure turbine, while eCore 1 contained an eight-stage compressor and a single-stage high-pressure turbine. “So eCore 1 is the CFM-type architecture; eCore 2 is the Leap-X architecture,” Klapproth explained. “So we take all the [lessons] from eCore 1 and design the hardware for eCore 2.”
CFM expects the third demonstrator to start running roughly a year after the start of eCore 2's testing. Looking much like eCore 2, with its 10-stage compressor and two-stage HP turbine, eCore 3 will undergo what Klapproth described as minor tweaks or tune-ups. “We'll find some areas in eCore2 that we can improve upon,” he said. “We'll make those changes and then test them and then we'll head into the product certification cycle.”