zh (Pinyin) tʂ (IPA)

Voiceless retroflex affricate
The voiceless retroflex affricate is a type of consonantal sound, used in some spoken languages. The symbol in the International Phonetic Alphabet that represents this sound is ⟨ʈ͡ʂ⟩, sometimes simplified to ⟨tʂ⟩, and the equivalent X-SAMPA symbol is ⟨ts`⟩.

The affricate occurs in a number of languages:

Slavic languages: Polish, Ukrainian, Belarusian, Old Czech, and some speakers of Russian and Serbo-Croatian may use it instead of the voiceless alveolo-palatal affricate.
a number of Northwest Caucasian languages have retroflex affricates that contrast in secondary articulations like labialization.
Mandarin and other Sinitic languages.

Some scholars transcribe the laminal variant of this sound as /t͡ʃ/, even though it is not palatalized. In such cases the voiceless palato-alveolar affricate is transcribed /t͡ʃʲ/.

Features of the voiceless retroflex affricate:

Its manner of articulation is sibilant affricate, which means it is produced by first stopping the air flow entirely, then directing it with the tongue to the sharp edge of the teeth, causing high-frequency turbulence.
Its place of articulation is retroflex, which prototypically means it is articulated subapical (with the tip of the tongue curled up), but more generally, it means that it is postalveolar without being palatalized. That is, besides the prototypical sub-apical articulation, the tongue contact can be apical (pointed) or laminal (flat).
Its phonation is voiceless, which means it is produced without vibrations of the vocal cords. In some languages the vocal cords are actively separated, so it is always voiceless; in others the cords are lax, so that it may take on the voicing of adjacent sounds.
It is an oral consonant, which means air is allowed to escape through the mouth only.
It is a central consonant, which means it is produced by directing the airstream along the center of the tongue, rather than to the sides.
The airstream mechanism is pulmonic, which means it is articulated by pushing air solely with the lungs and diaphragm, as in most sounds.