added Druckrohrleitungs class, based on ETH Code

Druckrohrleitung/Druckrohrleitung_functions.py

@@ -0,0 +1,17 @@
+import numpy as np 
+
+def simple_time_delay(delta_p_profile,delay,timestep):
+    rounded_delay = timestep * np.round(delay/timestep)
+    print('Delay was rounded to ', rounded_delay)
+    n_pad = int(rounded_delay/timestep)
+    output_delta_p_profile = np.pad(delta_p_profile[0:-n_pad],[n_pad,0],constant_values=0)
+    return output_delta_p_profile
+
+## testing
+if __name__ == "__main__":
+    delta_p_profile = np.ones([100])
+    delay = 4 
+    timestep = 0.2
+
+    print(simple_time_delay(delta_p_profile, delay, timestep))
+