If you put the queries within stored procedures and setup the stored procedures with the WITH RECOMPILE option the execution plan will be regenerated each time it’s run. This isn’t recommend as it will increase your CPU load as the execution plan needs to be recreated each time the query is run.
How much RAM does the SQL Server have? How much cache is being used for the buffer cache, and how much for the procedure cache?
If you want to flush the execution plans you can use the DBCC FreeBufferCache command.
Normally SQL will flush the commands with the oldest last run time when the procedure cache begins to fill.