The Query simulation method generates queries automatically.
He & Ounis has proposed method of query simulation in
B. He and I. Ounis. Term Frequency Normalisation Tuning for BM25 and DFR Models. In Proceedings of the 27th European Conference on Information Retrieval (ECIR'05). Santiago de Compostela, Spain. March, 2005.
The idea of the query simulation method is to extract the most informative terms from the documents that are related to a particular topic so that the generated query consists of meaningful words.