An anti-icing system for an inlet lip annularly extending about a nacelle of an aircraft engine assembly, comprising: an interior wall structure at least partially forming an annular anti-icing chamber with an internal surface of the inlet lip; an annular shield with a first end coupled to the interior wall structure, and a second end extending into the annular anti-icing chamber and being unattached to the interior wall structure or the inlet lip to form a passage between the second end of the annular shield and the internal surface of the inlet lip, the annular shield dividing the annular anti-icing chamber into a first chamber portion and a second chamber portion, the first and second chamber portions being fluidly coupled together by the passage formed between the second end and the internal surface of the inlet lip; wherein the annular shield has an inner surface and an outer surface such that the first chamber portion is formed by the inner surface of the annular shield and the interior wall structure and the second chamber portion is formed by the outer surface of the annular shield and the internal surface of the inlet lip; and a nozzle configured to be coupled to a source of heated air and extending through the interior wall structure at an inwardly radial position relative to the first end of the annular shield within the first chamber portion such that the heated air exits the nozzle into the first chamber portion in which the annular shield blocks direct impingement by the heated air on the internal surface of the inlet lip; wherein the nozzle includes a plurality of nozzle openings, including at least a first nozzle opening oriented in a tangential direction of the annular anti-icing chamber and a second nozzle opening that is oriented at an angle offset relative to the tangential direction of the annular anti-icing chamber. an interior wall structure at least partially forming an annular anti-icing chamber with an internal surface of the inlet lip; an annular shield with a first end coupled to the interior wall structure, and a second end extending into the annular anti-icing chamber and being unattached to the interior wall structure or the inlet lip to form a passage between the second end of the annular shield and the internal surface of the inlet lip, the annular shield dividing the annular anti-icing chamber into a first chamber portion and a second chamber portion, the first and second chamber portions being fluidly coupled together by the passage formed between the second end and the internal surface of the inlet lip; wherein the annular shield has an inner surface and an outer surface such that the first chamber portion is formed by the inner surface of the annular shield and the interior wall structure and the second chamber portion is formed by the outer surface of the annular shield and the internal surface of the inlet lip; and a nozzle configured to be coupled to a source of heated air and extending through the interior wall structure at an inwardly radial position relative to the first end of the annular shield within the first chamber portion such that the heated air exits the nozzle into the first chamber portion in which the annular shield blocks direct impingement by the heated air on the internal surface of the inlet lip; wherein the nozzle includes a plurality of nozzle openings, including at least a first nozzle opening oriented in a tangential direction of the annular anti-icing chamber and a second nozzle opening that is oriented at an angle offset relative to the tangential direction of the annular anti-icing chamber.