A fluid mixing device for mixing a first injection fluid and a second injection fluid, the fluid mixing device comprising: a first fluid inlet, a second fluid inlet, a mixing chamber, and an outlet port, characterized in that the first fluid inlet is configured to conduct the first injection fluid in a first direction along a first axis toward a first concave redirecting surface, the first fluid inlet having a first redirecting surface; the second fluid inlet is configured to conduct the second injection fluid in a second direction along a second axis different from the first axis and toward a second concave redirecting surface, the second fluid inlet having the second redirecting surface, wherein the first axis of the first direction and the second axis of the second direction are substantially parallel; the mixing chamber is in fluid communication with the first fluid inlet and the second fluid inlet and has a third concave redirecting surface at the proximal end of the mixing chamber, the mixing chamber is configured to mix the first injection fluid and the second injection fluid; and the outlet port is at a distal end of the fluid mixing device and in fluid communication with the mixing chamber and distal to the first fluid inlet and the second fluid inlet, wherein the first fluid inlet and the second fluid inlet have a first inlet port and a second inlet port, respectively, wherein the first redirecting surface and the second redirecting surface are positioned distally relative to the first inlet port and the second inlet port, respectively, and wherein the third redirecting surface is positioned proximally relative to the outlet port, the first redirecting surface, and the second redirecting surface, wherein the first redirecting surface is configured to redirect the first injection fluid in a first different direction from the first direction to enter the mixing chamber along the first different direction, and the second redirecting surface is configured to redirect the second injection fluid in a second different direction from the second direction to enter the mixing chamber along the second different direction, wherein the first different direction and the second different direction are selected so that the first injection fluid and the second injection fluid contact the third redirecting surface of the mixing chamber to turbulently mix the first injection fluid and the second injection fluid in the mixing chamber, and wherein a mixture of the first injection fluid and the second injection fluid exits the fluid mixing device through the outlet port in a direction along a third axis, wherein the third axis is substantially parallel with the first axis and the second axis. a first fluid inlet, a second fluid inlet, a mixing chamber, and an outlet port, characterized in that the first fluid inlet is configured to conduct the first injection fluid in a first direction along a first axis toward a first concave redirecting surface, the first fluid inlet having a first redirecting surface; the second fluid inlet is configured to conduct the second injection fluid in a second direction along a second axis different from the first axis and toward a second concave redirecting surface, the second fluid inlet having the second redirecting surface, wherein the first axis of the first direction and the second axis of the second direction are substantially parallel; the mixing chamber is in fluid communication with the first fluid inlet and the second fluid inlet and has a third concave redirecting surface at the proximal end of the mixing chamber, the mixing chamber is configured to mix the first injection fluid and the second injection fluid; and the outlet port is at a distal end of the fluid mixing device and in fluid communication with the mixing chamber and distal to the first fluid inlet and the second fluid inlet, wherein the first fluid inlet and the second fluid inlet have a first inlet port and a second inlet port, respectively, wherein the first redirecting surface and the second redirecting surface are positioned distally relative to the first inlet port and the second inlet port, respectively, and wherein the third redirecting surface is positioned proximally relative to the outlet port, the first redirecting surface, and the second redirecting surface, wherein the first redirecting surface is configured to redirect the first injection fluid in a first different direction from the first direction to enter the mixing chamber along the first different direction, and the second redirecting surface is configured to redirect the second injection fluid in a second different direction from the second direction to enter the mixing chamber along the second different direction, wherein the first different direction and the second different direction are selected so that the first injection fluid and the second injection fluid contact the third redirecting surface of the mixing chamber to turbulently mix the first injection fluid and the second injection fluid in the mixing chamber, and wherein a mixture of the first injection fluid and the second injection fluid exits the fluid mixing device through the outlet port in a direction along a third axis, wherein the third axis is substantially parallel with the first axis and the second axis.