caption: an open system is an actual heat source
exif: {"Image DocumentName": "Open system (control volume): A properly selected region in space.", "Image ImageDescription": "It usually encloses a device that involves mass flow such as a compressor, turbine, or nozzle. Both mass and energy can cross the boundary of a control volume. Control surface: The boundaries of a control volume. It can be real or imaginary. An open system (a control volume) with one inlet and one exit.", "Image XResolution": "37", "Image YResolution": "37", "Image ResolutionUnit": "Pixels/Centimeter", "Image Software": "SlidePlayer", "Image YCbCrPositioning": "Centered"}