A combustor for use in a gas turbine engine, the combustor enclosing a combustion chamber having a combustion area, wherein the combustor comprises: a shell having an inner surface and an outer surface opposite the inner surface, the shell comprising a primary aperture extending from the outer surface to the inner surface through the shell; and a heat shield panel comprising: a first surface; a second surface opposite the first surface of the heat shield panel; and a cooling circuit formed internally within the heat shield panel, the cooling circuit comprising an inlet at the second surface of the heat shield panel, an outlet at the first surface of the heat shield panel, an inward surface, and an outward surface, the inward surface and the outward surface being in a facing spaced relationship extending from the inlet to the outlet defining an airflow passageway therebetween, wherein the airflow passageway includes a parallel portion that is oriented about parallel to at least one of the first surface of the heat shield panel and the second surface of the heat shield panel and wherein the inward surface is configured to be closer to a combustion area of the gas turbine engine than the outward surface at the parallel portion; wherein the primary aperture of the shell is aligned with the inlet of the cooling circuit to direct airflow to said inlet of the cooling circuit; wherein the outward surface is oriented at an obtuse angle (α 1) relative to the first surface of the heat shield panel at the outlet; characterized in that: the cooling circuit further comprises a tripping device extending away from the outward surface at the parallel portion into the airflow passageway, the tripping device terminating within the airflow passageway prior to reaching the inward surface, wherein the cooling circuit does not comprise a tripping device extending away from the inward surface into the airflow passageway. a shell having an inner surface and an outer surface opposite the inner surface, the shell comprising a primary aperture extending from the outer surface to the inner surface through the shell; and a heat shield panel comprising: a first surface; a second surface opposite the first surface of the heat shield panel; and a cooling circuit formed internally within the heat shield panel, the cooling circuit comprising an inlet at the second surface of the heat shield panel, an outlet at the first surface of the heat shield panel, an inward surface, and an outward surface, the inward surface and the outward surface being in a facing spaced relationship extending from the inlet to the outlet defining an airflow passageway therebetween, wherein the airflow passageway includes a parallel portion that is oriented about parallel to at least one of the first surface of the heat shield panel and the second surface of the heat shield panel and wherein the inward surface is configured to be closer to a combustion area of the gas turbine engine than the outward surface at the parallel portion; wherein the primary aperture of the shell is aligned with the inlet of the cooling circuit to direct airflow to said inlet of the cooling circuit; wherein the outward surface is oriented at an obtuse angle (α 1) relative to the first surface of the heat shield panel at the outlet; characterized in that: the cooling circuit further comprises a tripping device extending away from the outward surface at the parallel portion into the airflow passageway, the tripping device terminating within the airflow passageway prior to reaching the inward surface, wherein the cooling circuit does not comprise a tripping device extending away from the inward surface into the airflow passageway. a first surface; a second surface opposite the first surface of the heat shield panel; and a cooling circuit formed internally within the heat shield panel, the cooling circuit comprising an inlet at the second surface of the heat shield panel, an outlet at the first surface of the heat shield panel, an inward surface, and an outward surface, the inward surface and the outward surface being in a facing spaced relationship extending from the inlet to the outlet defining an airflow passageway therebetween, wherein the airflow passageway includes a parallel portion that is oriented about parallel to at least one of the first surface of the heat shield panel and the second surface of the heat shield panel and wherein the inward surface is configured to be closer to a combustion area of the gas turbine engine than the outward surface at the parallel portion; wherein the primary aperture of the shell is aligned with the inlet of the cooling circuit to direct airflow to said inlet of the cooling circuit; wherein the outward surface is oriented at an obtuse angle (α 1) relative to the first surface of the heat shield panel at the outlet; characterized in that: the cooling circuit further comprises a tripping device extending away from the outward surface at the parallel portion into the airflow passageway, the tripping device terminating within the airflow passageway prior to reaching the inward surface, wherein the cooling circuit does not comprise a tripping device extending away from the inward surface into the airflow passageway.