I would like to run hadoop program in a hadoop cluster to test times. Is any free Hadoop Cluster available for experiments with big data for Academic use?
I doubt if there is something which is 100% free. One feasible way could be to use Amazon EC2 ready to use Hadoop cluster. It's not free but cheap enough to get your hands dirty. And if you don't want to pay anything, you could probably use Cloudera's VM and create a cluster using VMs on your machine. That would be a lot more convenient and cheaper as well.
HTH
Actually, there is a free cluster for Greek academics (I assume you are Greek), provided by GRNET, in case you haven't found it already. I have been using it for over two months:
https://okeanos.grnet.gr/home/
However, you'll probably have to setup everything by yourself, since I don't believe that there is a public image with hadoop.
UPDATE (for future reference): It seems that there is now an easy wizard-like way to set up a hadoop cluster, too.