In general all researcher using US dollar to calculate cash flows.... But if you are much comfortable with your country currency, then go ahead with that... No issue.......
Agree. that US$ would be the default currency. If using local currency, you can specify the relevant exchange rate, so that the audience could use it to convert if needed.
Usually US Dollar is used as a standard currency to calculate international flow of any good because of its stability and also because many countries have adopted this for standard trade.
But there are a few commodities which are not traded for dollars in the international market and if you wish to calculate the flows of those commodities, i suggest you to check the currency by which it is traded and use it to calculate the flows.
Dollar is widely used to calculate the flows, but you can also use the local currencies in which the particular ( asset ) trading for whom you are calculating flows.