Iranian nationality flight from the UK to Australia throughout Shanghai Pudong Airport

You are definitely and without any doubt eligible for 24 hour visa free transit and you do not need any kind of visa.

If you do not plan to leave the airport, you will just walk from your arrival flight to the gate with your departure flight and you will not be a subject of customs and immigration checks. The only formality will be a security checks between your two flights.

If you intend to exit the airport, the first thing you will do upon your landing in Shanghai will be to approach the transit counter where you will apply for a temporary entry permit where you will present your flight tickets and your accommodation booking confirmation if you plan to to stay at the hotel. This application is free of charge. Here you should be aware that the issuing of the temporary entry permit is not a passenger's right, but more a bonus that is offered to those with long layovers on the case by case situation. In other words, your application can be granted or denied without too much explanations.

In any case, you do not need a visa and you are ready to go with your passport, an Australian visa inside and the boarding passes. You do not need anything more than that. Have a nice journey.