Which Org-mode version are you using? I'm using the latest Org-mode version from source code branch `master`.
When I use your `:noweb-ref` style like this:
```org
* noweb reference with argument
#+BEGIN_SRC sh :var str="" :noweb-ref sh-print-something
echo "$str"
#+END_SRC
#+BEGIN_SRC sh :results output :noweb yes
echo "hello, "
<<sh-print-something(str="stardiviner")>>
#+END_SRC
#+RESULTS:
```
Emacs reports error:
org-babel-ref-resolve: Reference ‘sh-print-something’ not found in this buffer.
Org-mode version: Org mode version 9.0.8 (9.0.8-elpaplus @ /home/stardiviner/Code/Emacs/org-mode/lisp/)