If the application is authenticates using OAM, then the logout for the application can be configured as follows::
1) Configure the destination for the logout link as follows
<af:goLink text="Log out" destination="adfAuthentication?logout=true&end_url=/index.html"/>
2) Now goto MW_HOME/Oracle_WC1/common/bin and execute wlst.sh
3) Connect to admin server using connect('weblogic','password', 't3://host:adiminport')
4) Now run addOAMSSOProvider(loginuri="/${app.context}/adfAuthentication", logouturi="/oamsso/logout.html")
5) After successful run, restart the servers.